Data Item _diffrn_radiation.polarizn_Stokes_Q

General

Item name
_diffrn_radiation.polarizn_Stokes_Q
Category name
diffrn_radiation
Attribute name
polarizn_Stokes_Q
Required in PDB entries
no
Used in currrent PDB entries
No

Item Description

(Ip-In)*cos(2*theta), where where Ip is the intensity (amplitude squared) of the electric vector in the plane of polarization, In is the intensity (amplitude squared) of the electric vector in the plane of the normal to the plane of polarization, and theta is the angle as viewed from the specimen, between the normal to the polarization plane and the laboratory Y axis as defined in the AXIS category. This is an average or other representative sample of the scan. This is the second of the Stokes polarization parameters, I, Q, U, V (also known as I, M, C, S). See H. H. Berry, G. Gabrielse, A. E. Livingston (1977), "Measurement of the Stokes parameters of Light", Applied Optics, 16:12, 3200 -- 3205. If the absolute intensity is not known, the value 1. is assumed for I, and all 4 Stokes parameters are dimensionless. When the absolute intensity is known, all 4 Stokes parameters are in units of Watts per square meter.

Data Type

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