Support for bond orders

Jmol supports bond orders (i.e., different from single bonds) and displays them as parallel, solid or dashed, cylinders.

Visualization of non-single bonds can be supressed (all will show as single) if set showMultipleBonds off is issued at the console or from a script.

File formats that specify bond order --and Jmol recognizes as such:

• MOL specifies bond order natively, using certain numeric codes (see table below)
• MOL2 specifies bond order natively, using certain alphanumeric codes (see table below)
• PDB can do double bonds using a trick: specify twice each CONECT record, or put the second atom twice in the same record.

Jmol commands that assign bond order:

• connect accepts a parameter specifying bond type (see table below)
• bondOrder (new in Jmol 11.3.x) accepts a parameter specifying bond type (see table below)

bond order	Jmol syntax in connect and bondOrder	Jmol syntax in bondOrder	bond code in MOL file	bond code in MOL2 file
	hBond a	-1	n/a	n/a
0.5	partial a	0.5	8 d	n/a
1	single	1	1	1
1.5	partialDouble b	-1.5	5	n/a
1.5	aromatic b	1.5	4	ar
2	double	2	2	2
2.5	partialTriple ? c	2.5 or -2.5 b,c	n/a	n/a
3	triple	3	3	3
4	quadruple	4	n/a	n/a

Notes:

(a) "hBond" and "partial" are both dashed, but they have different patterns, and newly created hydrogen bonds are only thin lines (wireframe style).

(b) "partialDouble" and "aromatic" are identical except for which side of the bond is represented by a dashed line. Same applies to "2.5" and "-2.5".

(c) starting Jmol 11.3.28

(d) type 8 is defined as "any" in MOL format; most versions of Jmol will render that as partial.

Contributors

AngelHerraez, NicolasVervelle