// International Chemical Identifier KEY Regex, by lo sauer - lsauer.com
// The InChIKey, or hashed InChI, is a fixed length (25 character) condensed digital representation 
// of the InChI, which tries to be unique but is not human-comprehensible. It uses a BASE26  alphabet (Hexavigesimal)!
// The last character of an InChIKey is computed from the rest of the InChIKey 
// The InChIKey specification facilitates web searches for chemical compounds, owing to sufficiently unqiue referencing 
// of compounds with a concise key, which is problematic with the full-length InChI (e.g. GET url limit is 1600 chars)

// From the official documents ( http://chemdata.nist.gov/InChI/inchi-hash.pdf ):
	// "The InChIKey is a character signature based on a hash code of the InChI string. Also, this hash
	 // may serve as a checksum for verifying InChI, for example, after transmission over a network."
	 
	 // InChIKey has four (4) distinct components: a 14-character hash of the basic (Mobile-H)
	// InChI layer (without /p segment accounting for added or removed protons); a 8-character
	// hash of the remaining layers; a 1 character is a flag indicating selected features (e.g.
	// presence of fixed-H layer); a 1 character is a “check” character. The overall length of
	// InChIKey is fixed at 25 characters, including separator:
	// AAAAAAAAAAAAAA-BBBBBBBBCD

	// This is significantly shorter than a typical InChI string (for example, the average length
	// of InChI string for Pubchem collection is 146 characters).
	// --------------------------------
	// InChIKey layout is as follows:
	// --------------------------------
	// AAAAAAAAAAAAAA
	// First block (14 letters)
	// Encodes molecular skeleton (connectivity)
	// BBBBBBBB
	// Second block (8 letters)
	// Encodes proton positions (tautomers), stereochemistry, isotopomers, reconnected layer
	// C
	// Flag character
	// Indicates InChI version, presence of a fixed-H layer, isotopes, and stereochemical
	// information.
	// D
	// Check character, obtained from all symbols except delimiters, i.e. from
	// AAAAAAAAAAAAAABBBBBBBBC

	// All symbols except the delimiter (a dash, that is, a minus) are uppercase English letters
	// representing a “base-26” encoding.
// see also:http://en.wikipedia.org/wiki/Hexavigesimal

//InChiKey v1.2 length: 14-10-1
//InChIKey v1.2 for morphine is BQJCRHHNABKAKU-KBQPJGBKSA-N
var x = 'BQJCRHHNABKAKU-KBQPJGBKSA-N'
25===x.length && '-'===x[14]
&& !!x.match(/^([0-9A-Z\-]+)$/)
>false
//enzyme ligand Copper - InchiKey: RYGMFSIKBFXOCR-UHFFFAOYSA-N
var x = 'RYGMFSIKBFXOCR-UHFFFAOYSA-N'
27===x.length && '-'===x[14] && '-'===x[25]
&& !!x.match(/^([0-9A-Z\-]+)$/)
>true


//Collisions do occurs:
//see http://www.chemconnector.com/2011/09/01/an-inchikey-collision-is-discovered-and-not-based-on-stereochemistry/