The Standard Parameter File (SPF)

The SPF-format is a card image oriented file. The first four characters on a card specify the nature of the data that follow on that card. Data that are not needed for the current program are simply skipped. All data are free format.

TITL text

This text may be used for various titleing purposes. It may be overridden at any time by another TITL instruction.

CELL (wavelength) a b c alpha beta gamma

Optional wavelength and cell parameters in Angstroms and degrees respectively. No CELL card is needed for Angstrom data input. The wavelength is used for the calculation of the linear absorption coefficient.

CESD sig(a) sig(b) sig(c) sig(alpha) sig(beta) sig(gamma)

This optional card specifies standard deviations in the cell parameters. No CESD card is needed for Angstrom data. The cell e.s.d. is combined with the coordinate e.s.d. for the calculation of the e.s.d. in derived parameters.

SPGR space-group-name

Space group symbol. See Space Groups for more details.

LATT (P/A/B/C/I/F) (A/C)

First parameter specifies the Bravais lattice type and the second whether the lattice is acentric or centric.

SYMM symmetry-operation

Symmetry operation. See Space Groups.

ATOM atom_name x y z (pop) (sig(x) sig(y) sig(z)) (spop)

This specifies the positional parameters, the population and their estimated standard deviations. The atom_name should conform some rules in order to be acceptable since it is interpreted. The first one or two characters should correspond to an element name known to the program (see Appendix 3). The number of characters of the element type and the attached digital number cannot exceed four. ' and " are allowed as part of an atom name. Labels not conforming with the PLATON-rules are modified in a new label including the symbol #. The atom-name may contain parentheses enclosing the numerical part.

UIJ atom_name U11 U22 U33 U23 U13 U12

Anisotropic thermal parameters. Note the order of the components that is the same as in SHELXL93 but often different in other systems (such as the XRAY and XTAL systems).

TF = exp[-2*pi**2(U11*H**2(A*)**2+...+2*U12*H*K*(A*)(B*)+...)]

SUIJ atom_name sig(U11) sig(U22) sig(U33) sig(U23) .. sig(U12)

Estimated standard deviations for the anisotropic thermal parameters.

U atom_name U sig(U)

Isotropic temperature factor along with its associate standard deviation.

BIJ atom_name Beta11 Beta22 Beta33 Beta23 Beta13 Beta12

Anisotropic thermal parameters. Note the order of the components.

TF = exp[-(Beta11*H**2+Beta22*K**2+...+2*Beta12*H*K+...)]
Definition: Beta11 = 2*pi**2*astar**2
            Beta12 = 2*pi**2*astar*bstar.

SBIJ atom_name sig(Beta11) .. sig(Beta23) .. sig(Beta12)

Estimated standard deviations for the anisotropic thermal parameters.

B atom_name B sig(B)

Isotropic temperature factor along with its associate standard deviation.

Definition: B = 8*pi**2*U

TRNS -n.klm

Facility to influence the applied symmetry operation for the first atom in a new residue. (see terms and notations)

TRNS n.klm

When placed in front of an ATOM card this instruction will transform the input coordinates on that card by the named symmetry operation: n is the number of the symmetry operation and k,l,m are the translations. (see terms and notations)

TRNS T11 T12 T13 T21 T22 T23 T31 T32 T33 (SH1 SH2 SH3)

Transformation matrix on cell axis and origin shift to be applied to the data following (CELL parameters, atomic coordinates and thermal parameters).

Example:
TITL NI-COMPOUND
CELL NI .123 .544 -.176 1 .001 .002 .001 0.0
UIJ  NI .011 .013 .025 -.011 .004 .009
SUIJ NI .001 .001 .002 .002 .002 .001
ATOM C1 .345 .675 -.334 1 .010 .009 .005 0.0
U    C1 0.04 0.01
     (etc)