Data Item _phasing_MIR_der_refln.HL_D_iso

General

Item name
_phasing_MIR_der_refln.HL_D_iso
Category name
phasing_MIR_der_refln
Attribute name
HL_D_iso
Required in PDB entries
no
Used in currrent PDB entries
No

Item Description

The isomorphous Hendrickson-Lattman coefficient Diso for this reflection for this derivative. -2.0 * Fpobs2 * sin(alphahcalc)2 * cos(alphahcalc)2 Diso = ---------------------------------------- E2 E = (Fphobs - Fpobs - Fhcalc)2 for centric reflections = [(Fphobs - Fpobs) * 21/2 - Fhcalc]2 for acentric reflections Fpobs = the observed structure-factor amplitude of the native Fphobs = the observed structure-factor amplitude of the derivative Fhcalc = the calculated structure-factor amplitude from the heavy-atom model alphahcalc = the phase calculated from the heavy-atom model This coefficient appears in the expression for the phase probability of each isomorphous derivative: Pi(alpha) = exp[k + A * cos(alpha) + B * sin(alpha) + C * cos(2 * alpha) + D * sin(2 * alpha)] Ref: Hendrickson, W. A. & Lattman, E. E. (1970). Acta Cryst. B26, 136-143.

Data Type

Data type code
float
Data type detail
int item types are the subset of numbers that are the floating numbers.
Primitive data type code
numb
Regular expression
-?(([0-9]+)[.]?|([0-9]*[.][0-9]+))([(][0-9]+[)])?([eE][+-]?[0-9]+)?