Data Item _em_2d_crystal_entity.space_group_name_H-M

General

Item name
_em_2d_crystal_entity.space_group_name_H-M
Category name
em_2d_crystal_entity
Attribute name
space_group_name_H-M
Required in PDB entries
yes
Used in current PDB entries
Yes, in about 0.008 % of entries

Item Description

There are 17 plane groups classified as oblique, rectangular, square, and hexagonal. To describe the symmetry of 2D crystals of biological molecules, plane groups are expanded to equivalent noncentrosymmetric space groups. The 2D crystal plane corresponds to the 'ab' plane of the space group. Enumerated space group descriptions include the plane group number in parentheses, the H-M plane group symbol, and the plane group class.

Data Type

Data type code
line
Data type detail
char item types / multi-word items ...
Primitive data type code
char
Regular expression
[][ \t_(),.;:"&<>/\{}'`~!@#$%?+=*A-Za-z0-9|^-]*

Controlled Vocabulary

Allowed Value Details
C 1 2 (5) cm, rectangular
C 2 2 2 (9) c2mm, rectangular
P 1 (1) p1, oblique
P 1 2 (3) pm, rectangular
P 1 21 (4) pg, rectangular
P 2 (2) p2, oblique
P 2 2 2 (6) 2mm, rectangular
P 2 2 21 (7) p2mg, rectangular
P 2 21 21 (8) p2gg, rectangular
P 3 (13) p3, hexagonal
P 3 1 2 (14) p3m1, hexagonal
P 3 2 1 (15) p31m, hexagonal
P 4 (10) p4, square
P 4 2 2 (11) p4mm, square
P 4 21 2 (12) p4gm, square
P 6 (16) p6, hexagonal
P 6 2 2 (17) p6mm, hexagonal

Controlled Vocabulary at Deposition

Allowed Value Details
C 1 2 (5) cm, rectangular
C 2 2 2 (9) c2mm, rectangular
P 1 (1) p1, oblique
P 1 2 (3) pm, rectangular
P 1 21 (4) pg, rectangular
P 2 (2) p2, oblique
P 2 2 2 (6) 2mm, rectangular
P 2 2 21 (7) p2mg, rectangular
P 2 21 21 (8) p2gg, rectangular
P 3 (13) p3, hexagonal
P 3 1 2 (14) p3m1, hexagonal
P 3 2 1 (15) p31m, hexagonal
P 4 (10) p4, square
P 4 2 2 (11) p4mm, square
P 4 21 2 (12) p4gm, square
P 6 (16) p6, hexagonal
P 6 2 2 (17) p6mm, hexagonal