| HESS block/namelist for Hessian parameters | ||
|---|---|---|
| The Hessian needed for the Vibrational Frequency analysis (RUNFLG=15 in CNTRL block) is obtained numerically from the analytical gradient. | ||
| Parameter | Description | Default value |
| DIFSTEP | Step size for numerical differentiation of gradient | 1.0.10-6 |
| NDIF | Number of steps to take for numerical differentiation | 2 |