calcforce

apbs.input_file.calculate

Note

Some versions of this command have been ported to the new APBS syntax (see new_input_format):

Nonpolar calculations: see nonpolar.Nonpolar.calculate_forces for more information.
Polar calculations:
- Boundary element: see boundary_element.BoundaryElement.calculate_forces
- Finite difference: see finite_difference.FiniteDifference.calculate_forces
- Finite element: see finite_element.FiniteElement.calculate_forces

This optional keyword controls energy output from an apolar solvation calculation. The syntax is:

calcforce {flag}

where flag is a text string that specifies the types of force values to be returned:

no: (Deprecated) don't calculate any forces.
total: Calculate and return total electrostatic and apolar forces for the entire molecule.
comps: Calculate and return total electrostatic and apolar forces for the entire molecule as well as force components for each atom.

The possible outputs from calcforce are:

tot {n}: total force for atom n
qf {n}: fixed charge force for atom n
db {n}: dielectric boundary force for atom n
ib {n}: ionic boundary force for atom n

The values will be printed in three columns which correspond to the x, y, and z components of the force vector.

Note

This option must be used consistently (with the same flag value) for all calculations that will appear in subsequent print statements.