“partial_charge” selects atoms based on their assigned partial charges.

partial_charge > value
partial_charge < value
(partial_charge = value)

pc. > value
pc. < value
(pc. = value)

indicate partial_charge > 0.0
indicate pc. < -0.25
indicate (pc. = 0)

Due to parsing limitations, explicit parentheses must be used around expressions with equals signs “=” in order to distinguish them from assignment of a keyword parameter to a command.

formal_charge

Selections