The $compute block

The $compute block sets up a composite property and the associated component properties (see Component and Composite Properties). This block can appear multiple times in the input file.

The input parameters that are set in this block are listed below.

Block parameters

Parameter	Value Type	Description	Remarks
name	string	The name for the composite property.
type	string	The type of the composite property.
protocols	List[object reference]	(Type-specific) The names of the protocols on which the calculation of the component properties is based.	Depends on the protocols to which it refers. Each composite-property type requires different protocols; see below.
surrogate_model	object reference	The type of surrogate model used in the estimation of the component properties.
components	List[string]	(Required for custom properties only) The types of the component properties involved in the custom composite property.

Type density

Parameter	Value Type	Description	Remarks
protocols	object reference	The name of the protocol for which the property is calculated.	Depends on the protocol to which it refers. Read the protocol requirements in Density.

Type gamma

Parameter	Value Type	Description	Remarks
protocols	object reference	The name of the protocol for which the property is calculated.	Depends on the protocol to which it refers. Read the protocol requirements in Surface-tension Coefficient.

Type dg

Parameter	Value Type	Description	Remarks
protocols	object reference	The name of the protocol for which the property is calculated.	Depends on the protocol to which it refers. Read the protocol requirements in Free-energy Difference.
temperature	numerical	(Optional) The value of the reference temperature of the alchemical-transformation simulations. By default, it is inferred from the .mdp file of the production run.

Type dhvap

Parameter	Value Type	Description	Remarks
protocols	List[object reference, object reference, object reference]	The names of the protocols for which the liquid-phase potential energy, gas-phase potential energy and polarization-energy correction, respectively, are calculated.	Depends on the protocols to which it refers. Read the protocol requirements in Enthalpy of Vaporization. The calculation of the gas-phase potential energy and/or the polarization-energy correction can be ignored by using none as the corresponding protocol names.
nmols	numerical	The number of molecules in the liquid phase.
mu	numerical	(Optional) The experimental value of the molecular dipole moment in the gas phase (in cubic nanometers).	Required for polarization-energy correction.
alpha	numerical	(Optional) The value of the molecular isotropic polarizability in the gas-phase (in Debye).	Required for polarization-energy correction.
C	numerical	(Optional) The value of the additional constant corrections (in kJ per mole; default is 0.0).
temperature	numerical	(Optional) The value of the reference temperature. By default, it is inferred from the .mdp file of the production run of the liquid simulation.

Note

Parameters that are not listed above can also be supplied. They are not recognized by the program in any special way, but are parsed and made available in the Customization API, together with all the other block parameters, as an InputParameters object.

Example

See Tutorial for a commented example.