where the connections to be removed are n1-n2, n3-n4, n5-n6, etc. Thus if connections were to be removed between atoms 4 and 5, and between atoms 665 and 670, then CVB(4:-5;665:-670) would be used. If connections are needed, then don't use the minus sign. Thus if connections were needed between atoms 4 and 5, and between atoms 665 and 670, then CVB(4:5,665:670) would be used. CVB is also useful when PDBOUT is present. A topology sometimes has an unwanted connection between two chains. This prevents some of the residues being identified. To correct this fault, remove the unwanted connection using CVB. If there are a several unwanted connections , and these connections involve a specific element, then consider the alternative of using VDWM. to change the Van der Waals radius for that element.
Note that CVB is used only in the generation of a starting Lewis structure or in generating a PDB file. The presence of unrealistic connections in this structure will not normally give rise to an incorrect SCF.
See also SETPI to explicitly assign p bonds, and atom labels to explicitly assign charges.
See also LEWIS, CHARGES, METAL, VDWM,
CHARGE, XENO, and MOZYME
See also: Lewis Structures, MOZYME introduction