Difference between revisions of "Support for isotopes"

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(MOL/SDF reader reads M ISO lines for isotopes (Jmol 14.15.1))
 
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== Atom expressions ==
 
== Atom expressions ==
The general syntax is to prefix the element symbol with the isotopic mass. Examples: <code>_14C</code>, <code>_2H</code>, <code>_31P</code>. As a special case, <code>deuterium</code>, <code>tritium</code>, <code>_D</code>,  <code>_T</code> are also recognized (not for other elements).
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The general syntax is to prefix the element symbol with the isotopic mass. Examples: <code>_14C</code>, <code>_2H</code>, <code>_31P</code>. As special cases, <code>deuterium</code>, <code>tritium</code>, <code>_D</code>,  <code>_T</code> are also recognized (not valid for other elements).
 
:Examples:
 
:Examples:
* <code>select _H</code> will select all hydrogen isotopes
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* <code>select _H</code> will select all hydrogen isotopes; synonym: <code>select hydrogen</code>
* <code>select _2H</code> will select only <sup>2</sup>H (deuterium); synonyms: <code>select deuterium</code>, <code>select _D</code>
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* <code>select _1H</code> will select only <sup>1</sup>H (protium)
* <code>select _H and not (_2H,_3H)</code> will select only protium (<sup>1</sup>H); for that, you can also do <code>select _1H</code>
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* <code>select _2H</code> will select only <sup>2</sup>H; synonyms: <code>select deuterium</code>, <code>select _D</code>
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* <code>select _3H</code> will select only <sup>3</sup>H; synonyms: <code>select tritium</code>, <code>select _T</code>
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== CML format ==
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In the Chemical Markup Language, an isotope is specified with a string <tt>isotope=</tt> inside the <tt><atom</tt> tag, just before the <tt>x2=</tt> or <tt>x3=</tt> parameter. Jmol supports this piece of information.
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:Example:
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:<tt><atom id="a1" elementType="C" isotope="14" x3="0.1853"  y3="0.0096"  z3="0.4587"/></tt>
  
 
== MOL formats ==
 
== MOL formats ==
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:<tt>    5.2002    0.7282    3.0988 C  '''-1'''  0  0  0  0  0  0  0  0  0  0  0</tt>
 
:<tt>    5.2002    0.7282    3.0988 C  '''-1'''  0  0  0  0  0  0  0  0  0  0  0</tt>
  
2. ''(not supported by Jmol)'' Stating the isotope mass in an "M ISO" line at the end of the file, columns 15-16.
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2. ''(supported by Jmol since v. 14.15.1)'' Stating the isotope mass in an "M ISO" line at the end of the file, columns 15-16.
 
:Example, for <sup>15</sup>N:
 
:Example, for <sup>15</sup>N:
 
:<tt>M ISO  1  7  '''15''' </tt>
 
:<tt>M ISO  1  7  '''15''' </tt>
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:<tt>M ISO  1  7  '''14''' </tt>
 
:<tt>M ISO  1  7  '''14''' </tt>
 
:The "1" indicates the number of entries in the line. The "7" is the affected atom's serial number in the file.
 
:The "1" indicates the number of entries in the line. The "7" is the affected atom's serial number in the file.
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== MOL V3000 formats ==
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''This includes all formats based on the V3000 chemical table files (CTfiles) specification from MDL/Symyx, like <code>mol</code>, <code>sdf</code>, etc.''
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 +
Jmol supports the V3000 CTfile specification which sets an isotope mass in the atom line.
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:Example, for <sup>15</sup>N :
 +
:<tt>M  V30 3 N -0.7207 2.0817 0 0 MASS=15</tt>
  
 
== PDB format ==
 
== PDB format ==
 
D and T are recognized as element identifiers, both in the atom name field (column 14) and in the element field (column 78).
 
D and T are recognized as element identifiers, both in the atom name field (column 14) and in the element field (column 78).
 
There is no way in <code>pdb</code> format to specify isotopes for other elements.
 
There is no way in <code>pdb</code> format to specify isotopes for other elements.
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 +
== CIF format ==
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D and T are recognized as element identifiers, in the <code>_atom_site_type_symbol</code> field. There is no support for other isotopes.
  
 
== XYZ format ==
 
== XYZ format ==
Although not a standard feature of <code>xyz</code>, Jmol will accept a special extension of the format<ref>Bob Hanson, 25 Sep 2006, jmol-users list. A new file format: "isotope-xyz" or XYZI.</ref> where the isotope mass prefixes the element symbol.
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Although not a standard feature of <code>xyz</code>, Jmol will accept a special extension of the format<sup>1</sup> where the isotope mass prefixes the element symbol.
 
:Example:
 
:Example:
 
:<tt>13C    3.4  5.6  7.8</tt>
 
:<tt>13C    3.4  5.6  7.8</tt>
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:<tt>12C    3.2  3.3  3.3</tt>
 
:<tt>12C    3.2  3.3  3.3</tt>
  
 +
<sup>1</sup> Bob Hanson, 25 Sep 2006, jmol-users list. A new file format: "isotope-xyz" or XYZI.
  
 
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== HIN format ==
 
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Similarly to <code>xyz</code> format, if the isotope mass prefixes the element symbol, Jmol will read that isotope.
<references/>
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:Example:
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:<tt>atom 4 - C CA - -1 0.8030124 0.6530771 0 3 3 a 5 a 10 s </tt>
 +
:<tt>atom 5 - 14C CA - 0 0.8030125 -0.7433776 0 3 4 a 6 a 11 s </tt>
 +
:<tt>atom 6 - D H - 0 -0.4063521 2.45442 0 1 3 s </tt>

Latest revision as of 17:39, 28 April 2017

Jmol supports isotopes; they are identified when reading files (see supported formats below) and they can be selected using atom expressions. In addition, Jmol renders the most common isotopes in different colors (lighter and heavier isotopes receive, respectively, lighter and darker shades of the standard CPK color for the element).

Atom expressions

The general syntax is to prefix the element symbol with the isotopic mass. Examples: _14C, _2H, _31P. As special cases, deuterium, tritium, _D, _T are also recognized (not valid for other elements).

Examples:
  • select _H will select all hydrogen isotopes; synonym: select hydrogen
  • select _1H will select only 1H (protium)
  • select _2H will select only 2H; synonyms: select deuterium, select _D
  • select _3H will select only 3H; synonyms: select tritium, select _T

CML format

In the Chemical Markup Language, an isotope is specified with a string isotope= inside the <atom tag, just before the x2= or x3= parameter. Jmol supports this piece of information.

Example:
<atom id="a1" elementType="C" isotope="14" x3="0.1853" y3="0.0096" z3="0.4587"/>

MOL formats

This includes all formats based on the chemical table files (CTfiles) specification from MDL/Symyx, like mol, sdf, etc.

There are two methods to specify an isotope in the CTfile specification. Jmol supports the first one:

1. (supported by Jmol) Including the mass difference in the atom line, columns 35-36. Mass difference is the isotope mass minus the naturally abundant mass.

Example, for 15N (15-14 = 1):
5.2002 0.7282 3.0988 N 1 0 0 0 0 0 0 0 0 0 0 0
Example, for 14C (14-12 = 2):
5.2002 0.7282 3.0988 C 2 0 0 0 0 0 0 0 0 0 0 0
Example, for 11C (11-12 = -1):
5.2002 0.7282 3.0988 C -1 0 0 0 0 0 0 0 0 0 0 0

2. (supported by Jmol since v. 14.15.1) Stating the isotope mass in an "M ISO" line at the end of the file, columns 15-16.

Example, for 15N:
M ISO 1 7 15
Example, for 14C:
M ISO 1 7 14
The "1" indicates the number of entries in the line. The "7" is the affected atom's serial number in the file.

MOL V3000 formats

This includes all formats based on the V3000 chemical table files (CTfiles) specification from MDL/Symyx, like mol, sdf, etc.

Jmol supports the V3000 CTfile specification which sets an isotope mass in the atom line.

Example, for 15N :
M V30 3 N -0.7207 2.0817 0 0 MASS=15

PDB format

D and T are recognized as element identifiers, both in the atom name field (column 14) and in the element field (column 78). There is no way in pdb format to specify isotopes for other elements.

CIF format

D and T are recognized as element identifiers, in the _atom_site_type_symbol field. There is no support for other isotopes.

XYZ format

Although not a standard feature of xyz, Jmol will accept a special extension of the format1 where the isotope mass prefixes the element symbol.

Example:
13C 3.4 5.6 7.8
C 2.3 4.4 4.4
12C 3.2 3.3 3.3

1 Bob Hanson, 25 Sep 2006, jmol-users list. A new file format: "isotope-xyz" or XYZI.

HIN format

Similarly to xyz format, if the isotope mass prefixes the element symbol, Jmol will read that isotope.

Example:
atom 4 - C CA - -1 0.8030124 0.6530771 0 3 3 a 5 a 10 s
atom 5 - 14C CA - 0 0.8030125 -0.7433776 0 3 4 a 6 a 11 s
atom 6 - D H - 0 -0.4063521 2.45442 0 1 3 s

Contributors

AngelHerraez