CONSTR subblock in QUILD block

Constraints can be supplied in the CONSTR subblock of QUILD. Below are the different option that are possible:

QUILD
  CONSTR
    dist   1 2         0.9
    angle  1 2 3     120.0
    dihed  1 2 3 4   100.0
    x      1           0.0   ! only with idelocal=0
    y      1           0.0   ! only with idelocal=0
    z      1           0.0   ! only with idelocal=0
  SUBEND
END

The units of these constraints are determined by the parameters in the UNITS block. The numbers in this subblock refer like usual to the atom numbers, as they are found in the ATOMS block.

A special case is observed for LinearTransit calculations, as given in the example below.

QUILD
  nrlt 11
  CONSTR
    dist   1 2         1.0    2.0
    angle  1 2 3     120.0   70.0
  SUBEND
END

Here there are two LinearTransit coordinates, i.e. the distance between atoms 1 and 2 and the angle 1-2-3. The distance between atoms 1 and 4 is a simple constraint throughout the whole calculation.