new feature: {*}.find("MF", TRUE);
-- calculates EMPIRICAL formula
-- example:
$ load $glucose
$ print {*}.find("MF")
H 12 C 6 O 6
$ print {*}.find("MF",true)
H 2 C 1 O 1
new feature: {cell=555}.find("CellFormula");
-- calculates cell formula for specified unit cell
-- weights interior 1, face 1/2, edge 1/4, vertex 1/8
-- selection should be a single packed unit cell
-- fails with "?" if end result is not integral
-- example:
$ load quartz.cif packed
$ print {*}.find("cellFormula");
O 6 Si 3
new feature: {cell=555}.find("CellFormula", TRUE);
-- calculates empirical cell formula for specified unit cell
-- weights interior 1, face 1/2, edge 1/4, vertex 1/8
-- selection should be a single packed unit cell
-- fails with "?" if end result is not integral
-- example:
$ load quartz.cif packed
$ print {*}.find("cellFormula", true);
O 2 Si 1
new feature: label %O
-- lists all symmetry operators leading to this position (as a string)
-- if more than one operator (contains a comma), this is a special position
-- same as %[symmetry] but just a simple list of operators