Record Format

The ATOM records present the atomic coordinates for standard residues. They also present the occupancy and temperature factor for each atom. Heterogen coordinates use the HETATM record type. The element symbol is always present on each ATOM record; segment identifier and charge are optional.

COLUMNS        DATA TYPE       FIELD         DEFINITION
---------------------------------------------------------------------------------
 1 -  6        Record name     ATOM
 7 - 11        Integer         serial        Atom serial number.
13 - 16        Atom            name          Atom name.
17             Character       altLoc        Alternate location indicator.
18 - 20        Residue name    resName       Residue name.
22             Character       chainID       Chain identifier.
23 - 26        Integer         resSeq        Residue sequence number.
27             AChar           iCode         Code for insertion of residues.
31 - 38        Real(8.3)       x             Orthogonal coordinates for X in A.
39 - 46        Real(8.3)       y             Orthogonal coordinates for Y in A.
47 - 54        Real(8.3)       z             Orthogonal coordinates for Z in A.
55 - 60        Real(6.2)       occupancy     Occupancy.
61 - 66        Real(6.2)       tempFactor    Temperature factor.
73 - 76        LString(4)      segID         Segment identifier, left-justified.
77 - 78        LString(2)      element       Element symbol, right-justified.
79 - 80        LString(2)      charge        Charge on the atom.
         1         2         3         4         5         6         7         8
12345678901234567890123456789012345678901234567890123456789012345678901234567890
ATOM--00145 -N-- VAL A--25    --32.433--16.336--57.540--1.00--11.92     A1---N--
         1         2         3         4         5         6         7         8
12345678901234567890123456789012345678901234567890123456789012345678901234567890
ATOM    145  N   VAL A  25      32.433  16.336  57.540  1.00 11.92      A1   N
ATOM    146  CA  VAL A  25      31.132  16.439  58.160  1.00 11.85      A1   C
ATOM    147  C   VAL A  25      30.447  15.105  58.363  1.00 12.34      A1   C
ATOM    148  O   VAL A  25      29.520  15.059  59.174  1.00 15.65      A1   O
ATOM    149  CB AVAL A  25      30.385  17.437  57.230  0.28 13.88      A1   C
ATOM    150  CB BVAL A  25      30.166  17.399  57.373  0.72 15.41      A1   C
ATOM    151  CG1AVAL A  25      28.870  17.401  57.336  0.28 12.64      A1   C
ATOM    152  CG1BVAL A  25      30.805  18.788  57.449  0.72 15.11      A1   C
ATOM    153  CG2AVAL A  25      30.835  18.826  57.661  0.28 13.58      A1   C
ATOM    154  CG2BVAL A  25      29.909  16.996  55.922  0.72 13.25      A1   C
         1         2         3         4         5         6         7         8
12345678901234567890123456789012345678901234567890123456789012345678901234567890
HETATM 1357 MG    MG   168       4.669  34.118  19.123  1.00  3.16          MG2+
HETATM 3835 FE   HEM     1      17.140   3.115  15.066  1.00 14.14          FE3+