Format Support

This page summarizes MolOP’s built-in format support. Each format page describes the information that can be read or written, the supported scope, and known boundaries. The coverage statements are tested against the registered codecs.

Choose by workflowChoose by extension

• Start with xyz, sdf, or smi for structure files.
• Use gjf or orcainp for calculation inputs.
• Use g16log, g16fchk, orcaout, or xtbout for calculation results.
• Use fakeg when a Gaussian-like text rendering is required from parsed data.

Extensions are only candidate hints. .out and .log can belong to more than one QM output format, so content probing determines the final reader. See the table below for the complete extension-to-codec mapping.

Group	Formats	Summary
Structure formats	xyz, sdf, smi, cml	Coordinate/graph structure IO and rendering.
QM input formats	gjf, orcainp	Gaussian and ORCA input parsing and rendering.
QM output formats	g16log, g16fchk, orcaout, xtbout, fakeg	Gaussian log/fchk, ORCA, and xTB output parsing plus Gaussian-like rendering from parsed Gaussian output.
Special readers	OpenBabel fallback	Unknown-extension fallback through OpenBabel-compatible readers.

Format ID	Typical Extensions	Read	Write	Support Page
xyz	.xyz	Yes	Yes	XYZ
sdf	.sdf, .sd, .mol	Yes	Yes	SDF/MOL
smi	.smi, .txt	Yes	Yes	SMILES
gjf	.gjf, .gif, .com, .gau, .gjc	Yes	Yes	Gaussian input
g16log	.log, .out, .g16, .gal, .irc, .gau	Yes	No	Gaussian output
g16fchk	.fchk, .fch, .fck	Yes	No	Gaussian formatted checkpoint
orcainp	.inp	Yes	Yes	ORCA input
orcaout	.out, .log, .orcaout	Yes	No	ORCA output
xtbout	.out, .log, .xtbout	Yes	No	xTB output
cml	.cml	No	Yes	CML writer
fakeg	.fakeg	No	Yes	Gaussian-like renderer
OpenBabel fallback	Unknown or OpenBabel-supported extensions	Yes	No	OpenBabel fallback

Note

Suffixes are not always unique. For example .out and .log can be ORCA, xTB, or Gaussian output, and .gau can be Gaussian input or output. Reader selection uses extension candidates plus content checks; non-matching readers must raise FormatMismatchError so that the next candidate can be tried.