Protocol hessian

This protocol calculates and prints Hessian, the matrix of second derivatives of the energy. By default, it also writes it to a file that can be used as an input for the calculation of vibrational frequencies. Translational and rotational degrees of freedom are projected out from the calculated Hessian.

Keywords used

Keywords specific for this protocol:

Other keywords used by this protocol:


The following examples, along with all other files needed to run them, can be found in the directory cuby4/protocols/hessian/examples

# Hessian example 1

# This calculates Hessian of a water molecule (the geometry was previously
# optimized at this level). In addition to printing the Hessian in the output,
# it is also saved to file 'hessian.yaml' for further use.

job: hessian

interface: turbomole

method: hf
basisset: 6-31G
density_fitting: none
scf_convergence: 7
charge: 0

geometry: |
  O    0.000000000  -0.000000000  -0.014048498
  H    0.000000000   0.785163819   0.520087569
  H    0.000000000  -0.785163819   0.520087569

# Print also complete gradient (by default, only RMS is printed)
print: gradient