FREQ Keywords
| Keyword | Effect |
|---|---|
Hessian analytical|semi | Hessian source (default: analytical for RHF/UHF) |
Numerical | Force finite-difference Hessian |
Step r | Finite-difference step, Bohr (default 0.01) |
Temperature T | Temperature for thermochemistry, K (default 298.15) |
Pressure P | Pressure for thermochemistry, atm (default 1.0) |
Scale f | Frequency scaling factor for ZPE / thermal corrections |
SymmetryNumber N | Rotational symmetry number (default 1, auto-detected) |
Read file | Read Hessian from checkpoint file |
Save | Write Hessian to checkpoint after computation |
See FREQ Section for detailed descriptions and examples.