Calculate area per molecule for molecules in a specified plane.

areapermol [<name>] {[<mask1>] [nlayers <#>] | nmols <#>} [out <filename>] [{xy | xz | yz}]

[<name>] Data set name.
[<mask1>] Atom mask for selecting molecules. If any atom in a molecule is selected the whole molecule is selected.
[nlayers <#>] Number of layers of molecules. Total number of molecules used will be # molecules divided by # layers.
[nmols <#>] If <mask1> is not specified, the number of molecules to use when calculating area per molecule.
[out <filename>] Output file name.
[{xy|xz|yz}] Cross-section of box to calculate area of. Default is X-Y.

Calculate area per molecule as Area / # molecules. The area is determined from the specified cross-section of the box (X-Y by default). Currently the calculation is only guaranteed to work properly with orthorhombic unit cells.

For example, to get the area per molecule of residues named “OL” which are arranged in 2 layers:

areapermol OL_area :OL nlayers 2 out apm.dat