Protocol heat_of_formation

This protocol calculates standard heat of formation of a molecule, ΔfHO(298.15 K). It calls a harmonic vibrational calculation that provides the ZPVE and other thermodynamic contributions, and energy calculations of the molecule and the atoms it constitutes of.

To account for standard states of the elements, tabulated data are used. The complete procedure is described in ref. [1].


Input structure

The protocol requires following blocks in the input:

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/heat_of_formation/examples

# Heat of formation calculation example

# A complete calculation o heat of formation of a methane
# Fast DFT calculatiosn are used for demonstration

# Multistep protocol is used to optimize the moleculle before the
# thermochemistry calculation (which includes vibrational analysis)
job: multistep
steps: opt, thermo

# The same method is used for optimization end frequencies,
# here it is defined only one
shared_method: &method_setup
  interface: turbomole
  method: dft
  functional: b3-lyp
  basisset: def2-SVP
  charge: 0

# Geometry optimization step
  # Methane is built using SMILES
  geometry: smiles:C
  job: optimize
  opt_quality: 0.1
  <<: *method_setup

# Heat of formation calculation
  job: heat_of_formation
  print: energy_decomposition

  # Setup for the vibrational analysis
    <<: *method_setup
    # Analytic vibrations not available with RI:
    density_fitting: none

  # The energy itself can be calculated separately at better level
    <<: *method_setup
    # The energy is calculated in larger basis:
    basisset: def2-TZVPP

  # This is applied only to isolated atom calculations of energy,
  # in addition to the common 'calculation_ene' setup
    # The isolated atoms may be open-shell:
    spin_restricted: no