Usage Guide¶

This comprehensive guide covers all features and commands of OpenThermo with detailed examples and explanations.

Quick Start¶

Basic Usage:

# Calculate thermochemistry from quantum chemistry output
OpenThermo molecule.log

# Custom temperature and pressure
OpenThermo molecule.log -T 300 -P 2.0

# Get help
OpenThermo --help

Command-Line Options¶

Input and Output Options¶

``-E <value>``

Description: Override electronic energy
Units: Atomic units (a.u.)
Default: Use value from input file
Example: -E -76.384729

``-T <T>`` or ``-T <T1 T2 step>``

Description: Temperature specification
Units: Kelvin (K)
Default: 298.15 K
Examples: - -T 300 (single temperature) - -T 200 400 25 (scan from 200K to 400K in 25K steps)

``-P <P>`` or ``-P <P1 P2 step>``

Description: Pressure specification
Units: Atmospheres (atm)
Default: 1.0 atm
Examples: - -P 2.0 (single pressure) - -P 0.5 2.0 0.2 (scan from 0.5 to 2.0 atm in 0.2 atm steps)

Thermochemistry Options¶

Frequency Scaling Factors:

``-sclZPE <factor>``: Scale factor for ZPE frequencies (default: 1.0)
``-sclheat <factor>``: Scale factor for thermal energy frequencies (default: 1.0)
``-sclS <factor>``: Scale factor for entropy frequencies (default: 1.0)
``-sclCV <factor>``: Scale factor for heat capacity frequencies (default: 1.0)

Examples:

OpenThermo molecule.log -sclZPE 0.98 -sclheat 0.99

Low Frequency Treatment Options¶

``-lowvibmeth <mode>``

Description: Low frequency treatment method
Values: - 0 or Harmonic: Standard RRHO (harmonic approximation) - 1 or Truhlar: Truhlar’s QRRHO (frequency raising) - 2 or Grimme: Grimme’s entropy interpolation (default) - 3 or Minenkov: Minenkov’s entropy + energy interpolation - 4 or HeadGordon: Head-Gordon’s energy interpolation (+ optional entropy) [Experimental]
Example: -lowvibmeth 1 or -lowvibmeth Truhlar

``-ravib <value>``

Description: Raising value for low frequencies (Truhlar’s method)
Units: cm⁻¹
Default: 100.0
Example: -ravib 50.0

``-intpvib <value>``

Description: Interpolation frequency threshold for Grimme, Minenkov, and Head-Gordon methods
Units: cm⁻¹
Default: 100.0
Example: -intpvib 50.0

``-hg_entropy <bool>``

Description: Enable or disable entropy interpolation for the Head-Gordon method
Values: true/false or 1/0
Default: true
Example: -hg_entropy false

``-bav <preset>``

Description: Average moment of inertia (Bav) used in the free-rotor entropy term. Only applicable to the HeadGordon method (lowvibmeth=4).
Values: - grimme: I_av = 1×10⁻⁴⁴ kg m² (μ’_av from Grimme 2012, used by ORCA/xtb/GoodVibes/Shermo) - qchem: I_av = 2.79928×10⁻⁴⁶ kg m² (B_av = 1 cm⁻¹, as specified in the Q-Chem manual)
Default: qchem (for HeadGordon)
Example: -bav grimme

``-ipmode <mode>``

Description: Calculation mode
Values: - 0: Gas phase (include translational/rotational) - 1: Condensed phase (remove translational/rotational)
Default: 0
Example: -ipmode 1

``-imagreal <value>``

Description: Treat imaginary frequencies as real if |ν| < value
Units: cm⁻¹
Default: 0.0 (no treatment)
Example: -imagreal 50.0

Mass and Symmetry Options¶

``-massmod <type>``

Description: Default atomic mass assignment
Values: - 1: Element average mass - 2: Most abundant isotope mass - 3: Masses from input file (default)
Default: 3
Example: -massmod 2

``-PGname <name>``

Description: Force specific point group
Default: Auto-detect
Example: -PGname C2v

``-conc <string>``

Description: Concentration specification
Default: None
Example: -conc "2.5"

Output Control Options¶

``-prtlevel <level>``

Description: Controls the amount of information printed to the console
Values: - 0: Minimal — banner + final thermodynamic data only - 1: Default — parameter summary, compact system info (atom count, point group, frequency range), and final data - 2: Verbose — full system data (per-atom masses, full frequency list, moments of inertia, rotational constants) and component breakdown (Translation/Rotation/Vibration/Electronic sections) - 3: Full — everything in level 2 plus per-mode vibrational detail tables (automatically enables -prtvib 1 unless explicitly overridden)
Default: 1
Examples: - -prtlevel 0 (minimal output for scripting) - -prtlevel 2 (full output matching pre-0.001.1 behavior)

``-prtvib <mode>``

Description: Print vibration contributions
Values: - 0: No (default) - 1: Yes, to screen - -1: Yes, to basename.vibcon file
Default: 0
Example: -prtvib 1

``-outotm <mode>``

Description: Output OpenThermo format file
Values: - 0: No (default) - 1: Yes
Default: 0
Example: -outotm 1

OpenMP / Performance Options¶

``-omp-threads <N>``

Description: Set the number of OpenMP threads for parallel computation
Default: Half of the detected physical CPU cores (minimum 1), or half of scheduler-allocated CPUs on HPC
HPC scheduler support: Automatically detects allocated CPUs from SLURM_CPUS_PER_TASK, PBS_NUM_PPN, PBS_NP, NSLOTS, LSB_DJOB_NUMPROC
Behavior: - If not specified: uses half of effective cores (scheduler allocation or physical) - If N ≤ effective cores: uses N threads - If N > effective cores: clamps to default (half) with a warning
Strategy auto-selection: OpenThermo automatically selects the best parallelization strategy: - Outer (T/P scan parallel): when many T/P scan points are available (≥ nthreads) - Inner (vibrational parallel): when few T/P points but many frequencies (>50)
Precedence: CLI -omp-threads > settings.ini omp-threads > auto-detect
Examples: - -omp-threads 4 (use 4 threads, if ≤ effective cores) - -omp-threads 2 (use 2 threads)

Help Options¶

``–help``

Description: Show general help
Example: OpenThermo --help

``–help-<option>``

Description: Show help for specific option
Examples: - --help-T (temperature help) - --help-lowvibmeth (low frequency help) - --help-input (input formats help)

Configuration Files¶

Configuration File Support¶

OpenThermo supports configuration through:

Command-line arguments (highest priority)
Local settings file: ./settings.ini
Environment settings: $OPENTHERMOPATH/settings.ini
Program defaults (lowest priority)

Creating Settings File¶

Generate a default settings file:

OpenThermo --create-config

This creates settings.ini with all available parameters and their default values.

Settings File Format¶

# OpenThermo Settings File
# Lines starting with # are comments

# Electronic energy override
E = -76.384729

# Temperature settings (K)
T = 298.15
# For temperature scan: T = 200.0 400.0 25.0

# Pressure settings (atm)
P = 1.0
# For pressure scan: P = 0.5 2.0 0.2

# Frequency scaling factors
sclZPE = 1.0      # Zero-point energy scaling
sclheat = 1.0     # Thermal energy scaling
sclS = 1.0        # Entropy scaling
sclCV = 1.0       # Heat capacity scaling

# Low frequency treatment
lowvibmeth = Grimme  # 0/Harmonic=RRHO, 1/Truhlar, 2/Grimme, 3/Minenkov, 4/HeadGordon
ravib = 100.0     # Raising threshold for Truhlar method
intpvib = 100.0   # Interpolation threshold for Grimme/Minenkov/HeadGordon
hg_entropy = true # Enable entropy interpolation for Head-Gordon method
# bav = qchem    # Bav for HeadGordon only: grimme or qchem (default: qchem). Ignored for Grimme/Minenkov.

# Calculation options
ipmode = 0         # 0=gas phase, 1=condensed phase
imagreal = 0.0    # Imaginary frequency threshold
massmod = 3       # Mass assignment: 1=average, 2=abundant, 3=file
PGname = "?"     # Point group (auto-detect if "?")

# Output options
prtlevel = 1      # Verbosity: 0=minimal, 1=default, 2=verbose, 3=full
prtvib = 0        # Vibration contributions: 0=no, 1=screen, -1=file
outotm = 0        # Output .otm file: 0=no, 1=yes

# Concentration (for solution phase)
conc = 1.0

# VASP energy selection
# false/no/0 = energy  without entropy (default), true/yes/1 = energy(sigma->0)
extrape = false

# OpenMP threading (command-line or settings.ini)
# Default: half of physical CPU cores or scheduler-allocated CPUs
# On HPC: SLURM_CPUS_PER_TASK / PBS_NP / NSLOTS are auto-detected
# omp-threads = 4
# Override with CLI: -omp-threads N (takes precedence)
# Strategy (outer T/P vs inner vibrational) is auto-selected

# Mass modifications (optional section)
# modmass
# 1 H 1.007825  # Atom 1: Hydrogen with specific mass
# 2 C 12.0      # Atom 2: Carbon-12 isotope

Configuration Parameters¶

Configuration Parameters¶
Parameter	Meaning	Default Value
`conc`	Concentration string for solution phase Gibbs energy corrections	`0`
`prtlevel`	Output verbosity level (0=minimal, 1=default, 2=verbose, 3=full)	`1`
`prtvib`	Print vibration contributions (0=no, 1=screen, -1=file)	`0`
`lowvibmeth`	Low frequency treatment method	`2`
`massmod`	Mass assignment mode (1=average, 2=abundant, 3=file)	`3`
`outotm`	Output .otm file flag (0=no, 1=yes)	`0`
`ipmode`	Calculation mode (0=gas phase, 1=condensed phase)	`0`
`T`	Temperature in Kelvin	`298.15`
`P`	Pressure in atmospheres	`1.0`
`sclZPE`	ZPE scaling factor	`1.0`
`sclheat`	Thermal energy scaling factor	`1.0`
`sclS`	Entropy scaling factor	`1.0`
`sclCV`	Heat capacity scaling factor	`1.0`
`ravib`	Raising threshold for Truhlar method (cm⁻¹)	`100.0`
`intpvib`	Interpolation threshold for Grimme/Minenkov/HeadGordon (cm⁻¹)	`100.0`
`hg_entropy`	Entropy interpolation for Head-Gordon method	`true`
`bav`	Bav preset for HeadGordon free-rotor entropy (grimme/qchem)	`qchem`
`imagreal`	Imaginary frequency threshold (cm⁻¹)	`0.0`
`Eexter`	External electronic energy override (a.u.)	`0.0`
`extrape`	VASP electronic energy selection	`false`
`PGname`	Point group name (“?” for auto-detect)	`"?"`
`omp-threads`	OpenMP thread count (clamped to effective cores)	Half of effective cores

Input File Formats¶

Supported Formats¶

1. OpenThermo Format (.otm)

Native format containing all molecular data:

<E>  //Electronic energy (a.u.)
-76.384729

<frequency>  //Wavenumbers (cm^-1)
1234.5
2345.6
...

<system>  //Name, mass (amu), X, Y, Z (Angstrom)
C   12.000000   0.000000   0.000000   0.000000
H    1.007825   0.000000   0.000000   1.089000
...

<elevel>  //Energy (eV) and degeneracy
0.0 1
1.5 3

2. Quantum Chemistry Output Files

Gaussian (.log, .out)

Requirements: Frequency analysis output
Extracts: Geometry, frequencies, electronic energy
Features: Automatic format detection

ORCA (.out)

Requirements: Frequency calculation results
Features: Supports various ORCA output formats

GAMESS-US (.log)

Requirements: Hessian/frequency analysis
Features: Standard GAMESS output parsing

NWChem (.out)

Requirements: Frequency analysis output
Features: Comprehensive NWChem support

CP2K (.out)

Requirements: Vibrational analysis output
Features: Supports molecular and periodic systems
Note: For condensed phase systems (ipmode=1): contributions of translation and rotation are ignored

VASP (OUTCAR)

Requirements: Vibrational analysis output in OUTCAR, system information in CONTCAR
Features: Supports molecular and periodic systems
Note: For condensed phase systems (ipmode=1): contributions of translation and rotation are ignored

Q-Chem (.out)

Requirements: Frequency calculation output (standalone FREQ job or combined OPT+FREQ two-job file)
Extracts: Geometry from last Standard Nuclear Orientation block (converged structure), SCF energy, spin multiplicity, atomic masses
Features: Supports gas-phase and implicit solvent (SMD/PCM) jobs; negative (imaginary) frequencies handled correctly
Note: Energy used is SCF energy = (G_ENP), not Total energy which includes non-electrostatic solvation corrections

3. List Files (.txt)

Batch processing of multiple files:

molecule-a.log
molecule-b.out
/path/to/molecule-c.otm

File Detection¶

Automatic: Program detects format from file content
No manual specification required
Priority: OpenThermo → specific program signatures

Output Files and Formats¶

Console Output¶

Example console output:

OpenMP threads: 24 (default: half of 48 physical cores). Use -omp-threads N to override.

                   --- Summary of Current Parameters ---

Running parameters:
 Print level: 1 (0=minimal, 1=default, 2=verbose, 3=full)
Printing individual contribution of vibration modes: No
 Temperature:          298.150 K
 Pressure:             1.000 atm
 Scaling factor of vibrational frequencies for ZPE:         1.0000
 Scaling factor of vibrational frequencies for U(T)-U(0):   1.0000
 Scaling factor of vibrational frequencies for S(T):        1.0000
 Scaling factor of vibrational frequencies for CV:          1.0000
 Low frequencies treatment: Grimme's interpolation for entropy
 Vibrational frequency threshold used in the interpolation is 100.00 cm^-1
                      -------- End of Summary --------

OpenThermo started to process BIH-conformers-1.log at Tue Feb 17 14:10:27 2026

                    -------- Chemical System Data -------
                    -------------------------------------
 Electronic energy:      -690.56452500 a.u.
 Electronic energy level 1     E =     0.000000 eV     Degeneracy =   1
 Atoms: 33 (16 H, 15 C, 2 N)  Total mass: 224.131420 amu
 Point group: Cs     Rotational symmetry number:   1
 Frequencies: 93 (range: 25.1 -- 3233.0 cm^-1)


                         ----------------------------
                         -------- Final data --------
                         ----------------------------
 Total q(V=0):        8.578987e+42
 Total q(bot):        8.806492e-87
 Total q(V=0)/NA:     1.424574e+19
 Total q(bot)/NA:    1.462352e-110
 Total CV:     237.069 J/mol/K      56.661 cal/mol/K
 Total CP:     245.383 J/mol/K      58.648 cal/mol/K
 Total S:      484.246 J/mol/K     115.738 cal/mol/K    -TS:   -34.507 kcal/mol
 Zero point energy (ZPE):    736.269 kJ/mol    175.973 kcal/mol   0.280430 a.u.
 Thermal correction to U:    773.673 kJ/mol    184.912 kcal/mol   0.294677 a.u.
 Thermal correction to H: 776.152210 kJ/mol 185.504830 kcal/mol   0.295621 a.u.
 Thermal correction to G: 631.774188 kJ/mol 150.997655 kcal/mol   0.240630 a.u.
 Electronic energy:       -690.5645250 a.u.
 Sum of electronic energy and ZPE, namely U/H/G at 0 K:       -690.2840949 a.u.
 Sum of electronic energy and thermal correction to U:        -690.2698485 a.u.
 Sum of electronic energy and thermal correction to H:        -690.2689043 a.u.
 Sum of electronic energy and thermal correction to G:        -690.3238950 a.u.

Calculation completed at: Tue Feb 17 14:10:27 2026

                    ---------- Happy calculation ----------
                    ---- OpenThermo normally terminated ---

Generated Files¶

basename.UHG (Temperature/Pressure Scan)

Thermal corrections and total energies:

Ucorr, Hcorr and Gcorr are in kcal/mol; U, H and G are in a.u.

     T(K)     P(atm)    Ucorr     Hcorr     Gcorr            U                H                G
   298.15     1.000     4.567     4.789     4.123   -76.380162   -76.379940   -76.384063
   323.15     1.000     5.123     5.345     4.567   -76.379506   -76.379284   -76.383851

basename.SCq (Temperature/Pressure Scan)

Entropy and partition functions:

S, CV and CP are in cal/mol/K; q(V=0)/NA and q(bot)/NA are unitless

    T(K)     P(atm)      S         CV        CP       q(V=0)/NA      q(bot)/NA
   298.15     1.000    45.67     12.34     13.56   1.234567e-05   2.345678e-03
   323.15     1.000    48.90     13.45     14.67   1.456789e-05   2.567890e-03

basename.vibcon (Vibration Contributions)

Individual mode contributions (when prtvib = 1 or -1):

Vibrational mode contributions at 298.15 K:

Mode     Freq(cm-1)    ZPE(kJ/mol)    U-T(kJ/mol)    S(J/mol/K)    CV(J/mol/K)
   1        456.7         0.005         0.008         2.34         1.23
   2        789.0         0.008         0.012         3.45         2.34
   ...

*.otm (OpenThermo Format)

Native format file (when outotm = 1):

<E>  //Electronic energy (a.u.)
-76.384729

<frequency>  //Wavenumbers (cm^-1)
456.7
789.0
...

<system>  //Name, mass (amu), X, Y, Z (Angstrom)
C   12.000000   0.000000   0.000000   0.000000
H    1.007825   0.000000   0.000000   1.089000
...

Thermochemistry Calculation Methods¶

Standard RRHO Model¶

Rigid-Rotor Harmonic Oscillator approximation

Partition Functions:

Translational: q_trans = (2πmkT/h²)^(3/2) * V
Rotational: q_rot = √(πI_a I_b I_c (kT/h²)^3) / σ (non-linear)
Vibrational: q_vib = ∏(1 - exp(-hν_i/kT))⁻¹
Electronic: q_elec = ∑ g_i exp(-ε_i/kT)

Thermodynamic Properties:

ZPE: ∑ (1/2) h ν_i
Thermal Energy: U - U(0) = RT² ∂(ln Q)/∂T
Entropy: S = R ln Q + RT ∂(ln Q)/∂T
Heat Capacity: CV = T ∂S/∂T

Quasi-RRHO Treatments¶

1. Truhlar’s QRRHO Method (``lowvibmeth = 1``)

Frequency raising approach:

Frequencies below threshold (ravib) are raised to ravib value
Applied to: ZPE, thermal energy, entropy, heat capacity
Mathematical: Replace ν < ν_threshold with ν_threshold
Advantage: Simple and computationally efficient

2. Grimme’s Interpolation (``lowvibmeth = Grimme``)

Entropy interpolation between RRHO and free rotor:

Weighting: w = 1 / (1 + (ν_threshold/ν)^4)
Entropy: S = w × S_RRHO + (1-w) × S_free
Free rotor entropy: S_free = R [ 1/2 + ln(√(8π³I kT / h²)) ]
Moment of inertia I: Uses Bav = 1×10⁻⁴⁴ kg m² (Grimme’s original μ’_av, fixed for this method)
Threshold: Configurable via intpvib parameter

3. Minenkov’s Interpolation (``lowvibmeth = 3``)

Extended Grimme’s method with energy interpolation:

Same entropy treatment as Grimme’s
Additional energy interpolation: U = (1/α) U_RRHO + (1-1/α) U_free
Where: α = 1 + (ν_threshold/ν)^4
Free rotor energy: U_free = RT/2
Note: ZPE = 0 for free rotor contribution

4. Head-Gordon’s Interpolation (``lowvibmeth = 4``)

Energy interpolation with optional entropy interpolation (Li et al., 2015):

Energy interpolation: U = w × U_RRHO + (1-w) × U_free
Weighting: w = 1 / (1 + (ν_threshold/ν)^4) (same damping function as Grimme/Minenkov)
Free rotor energy: U_free = RT/2
ZPE handling: ZPE is folded into the interpolated total vibrational energy (damped for low-frequency modes, as per eq. 4 of the paper). Separate ZPE is not displayed.
Cv interpolation: Cv = w × Cv_HO + (1-w) × R/2
Optional entropy interpolation (hg_entropy = true, default): uses the same Grimme free-rotor entropy formula
Entropy off (hg_entropy = false): entropy uses the standard harmonic oscillator model (paper’s original behavior)
Bav: Configurable via -bav option (only for this method): - qchem (default): I_av = 2.79928×10⁻⁴⁶ kg m² (B_av = 1 cm⁻¹, Q-Chem manual) - grimme: I_av = 1×10⁻⁴⁴ kg m² (Grimme 2012)
Threshold: Configurable via intpvib parameter
Reference: Li, Guo, Head-Gordon, Bell, J. Phys. Chem. C, 2015

Usage Examples¶

Basic Calculations¶

# Standard calculation at 298.15 K, 1 atm
OpenThermo water.log

# Custom conditions
OpenThermo methane.out -T 300 -P 2.0

# High precision calculation
OpenThermo benzene.otm -T 298.15 -lowvibmeth 2 -sclZPE 0.98

Advanced Calculations¶

# Temperature scan with Grimme's method
OpenThermo molecule.log -T 200 400 25 -lowvibmeth 2

# Pressure scan with custom scaling
OpenThermo molecule.log -P 0.1 10 0.5 -sclS 0.99 -sclCV 0.99

# Transition state calculation
OpenThermo ts.out -imagreal 100 -lowvibmeth 1 -ravib 50

# Condensed phase calculation
OpenThermo crystal.out -ipmode 1 -conc "1.0 M"

# Minimal output (final data only)
OpenThermo molecule.log -prtlevel 0

# Verbose output with per-mode vibration detail
OpenThermo molecule.log -prtlevel 3

Batch Processing Examples¶

# Process all .log files in directory
ls *.log > files.txt
OpenThermo files.txt

# Custom analysis for multiple molecules
OpenThermo molecules.txt -T 298 -lowvibmeth 3 -prtvib 1 -outotm 1

Settings File Examples¶

# Standard thermochemistry
T = 298.15
P = 1.0
lowvibmeth = Grimme
sclZPE = 1.0

# High-precision calculation
T = 298.15
P = 1.0
lowvibmeth = Minenkov
sclZPE = 0.98
sclheat = 0.99
sclS = 0.99
sclCV = 0.99

# Head-Gordon quasi-RRHO (energy + entropy)
T = 298.15
P = 1.0
lowvibmeth = HeadGordon
intpvib = 100.0
hg_entropy = true

# Low temperature analysis
T = 100
P = 1.0
lowvibmeth = 1
ravib = 50.0

Advanced Features¶

Temperature and Pressure Scanning¶

# Temperature range
OpenThermo molecule.log -T 200 400 25

# Pressure range
OpenThermo molecule.log -P 0.5 2.0 0.2

# Combined range
OpenThermo molecule.log -T 273 373 50 -P 0.5 2.0 0.5

Mass Modifications¶

Custom atomic masses in settings.ini:

modmass
H 1.007825  # Atom 1: Hydrogen with specific mass
C 12.0      # Atom 2: Carbon-12
O 15.994915 # Atom 3: Oxygen-16

Symmetry Analysis¶

Automatic detection of point groups
Manual override with -PGname option
Rotational symmetry number calculation
Linear molecule detection

Imaginary Frequency Handling¶

Automatic detection of imaginary frequencies
Optional treatment as real frequencies
Configurable threshold with -imagreal option

VASP Energy Selection¶

Energy line format: In VASP OUTCAR files, the energy line contains two values:

energy  without entropy=      -27.39346935  energy(sigma->0) =      -27.39346935

Selection options: - extrape = false (default): Use first energy value (4th token) - extrape = true: Use last energy value (final token)
Configuration: Set in settings.ini or use default behavior

Batch Processing¶

Process multiple files:

# Create file list
echo "molecule-1.log" > batch.txt
echo "molecule-2.out" >> batch.txt
echo "molecule-3.otm" >> batch.txt

# Process batch
OpenThermo batch.txt

Troubleshooting¶

Common Issues¶

1. File Not Found

Error: Error: Unable to find molecule.log

Solution:

Check file path and spelling
Ensure file is in current directory or provide full path
For .txt batch files, verify all listed files exist

2. Unrecognized Program Format

Error: Error: Unable to identify the program that generated this file

Solution:

Verify the input file contains frequency analysis output
Check if the quantum chemistry program is supported
Ensure the calculation completed successfully

3. Invalid Arguments

Error: Error: Invalid value for -T

Solution:

Check argument syntax: -T 298.15 (single) or -T 200 400 25 (range)
Ensure numeric values are valid
Use --help-T for detailed syntax

4. Compilation Errors

Error: Undefined references or compilation failures

Solution:

Ensure all source files are present
Check compiler compatibility (GCC 7+, Intel, Clang)
Run make clean && make to rebuild
Verify Makefile is in the correct directory

5. Settings File Issues

Warning: Warning: settings.ini cannot be found

Solution:

Create settings.ini in current directory
Set OPENTHERMOPATH environment variable
Use -noset to skip settings loading

Performance Issues¶

Large Files

Enable batch processing with smaller chunks
Build with OpenMP (make OPENMP=1) for temperature/pressure scans
Use -omp-threads N to control thread count (default: half of physical cores)
For dedicated compute nodes, use -omp-threads with the full core count for maximum performance
On shared HPC headnodes, the conservative default (half cores) prevents overloading

Validation¶

Compare Results

Use different low frequency treatments (lowvibmeth 0,1,2,3)
Compare with literature values
Validate against experimental data

Debug Output

Use -prtlevel 2 or -prtlevel 3 for more detailed output
Use -prtvib 1 for detailed vibration analysis (auto-enabled at level 3)
Check basename.vibcon for individual contributions
Review scan files for temperature/pressure dependence