InChIKey

Non-Scalar Structural

The International Chemical Identifier Key (InChIKey) of a material is derived from the InChI. It is a 27 character non-human readable condensed digital representation of the InChI, also known as a hash.1

Notation

The InChIKey is a 14-8-1 character string. The first 14 characters represent the connectivity and charge information. The next 8 character represent the remaining sublayer information. The final character represents the kind of InChIKey being generated, including the version of InChI used.

The 14-8-1 Character string is represented as follows:

1
XXXXXXXXXXXXXX-YYYYYYYYFV-P

Examples

Methane (CH4)2

InChIKey: VNWKTOKETHGBQD-UHFFFAOYSA-N 

1
2
3
4
5
  H      0.5288      0.1610      0.9359
  C      0.0000      0.0000      0.0000
  H      0.2051      0.8240     -0.6786
  H      0.3345     -0.9314     -0.4496
  H     -1.0685     -0.0537      0.1921

Water (H2O)3

InChIKey: XLYOFNOQVPJJNP-UHFFFAOYSA-N 

1
2
3
H    0.7493682    0.0000000    0.4424329
O    0.0000000    0.0000000   -0.1653507
H   -0.7493682    0.0000000    0.4424329

Schema

The JSON schema and an example representation for this property can be found here.

  1. Wikipedia International Chemical Identifier (Website) ↩

  2. NIST CH4 (Website) ↩

  3. NIST H2O (Website) ↩