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Interface Composite

This interface performs multiple calculations on the system using different methods. The results are then combined according to an user-defined formula. It is possible to work with both total; energy and its components.



Each calculation should be specified in the input in a subsection calculation_method_name. The equation uses ruby syntax. Results of the calculations are accessible in variables named with the method name. These variables are hashes containing all the energy components (index is symbol corresponding to the component name). The total energy can be accessed as method_name[:energy]


Here is sample input for MP2/CBS extrapolation (Halkier et al. 1998) with CCSD(T) correction in smaller basis set.

interface: composite

charge: 0

  - mp2t
  - mp2q
  - cc

composite_equation: "
  mp2q[:scf_energy] +
  (3**3 * mp2t[:mp2_corr_energy] - 4**3 * mp2q[:mp2_corr_energy])/(3**3 - 4**3) +
  (cc[:ccsdt_corr_energy] - cc[:mp2_corr_energy])"

  interface: molpro
  method: mp2
  density_fitting: yes
  basisset: aug-cc-pVTZ

  interface: molpro
  method: mp2
  density_fitting: yes
  basisset: aug-cc-pVQZ

  interface: molpro
  method: ccsdt
  basisset: aug-cc-pVDZ