msCount problem in chemical terms column

User 677b9c22ff

15-11-2006 22:18:12

Hi,

adding terms like msCount('1.0') msCount('7.0') msCount('14.0') into a column always results in the same number of microscpecies, which is certainly not true. Should I change the field definition to someting else, or change type to real (its now integer). I suspect it just counts the number but does not take my pH value into account.

Tobias

User 851ac690a0

16-11-2006 12:47:22

Hi,

microspecies count does not depend on the pH!

microspecies distribution do depend on the pH!

microspecies count = 2^N , where N is the number of the ionizable atoms in the molecule.

Jozsi

ChemAxon e08c317633

16-11-2006 13:17:03

Tobias,

Check the ms and msDistr Chemical Terms functions. I think this is what you need.

Example (calculation of microspecies distribution at pH=1):

Code:

$ evaluate -e "msCount()" "NCC(O)=O"

4

$ evaluate -e "ms('1',0)" "NCC(O)=O"

[NH3+]CC(O)=O

$ evaluate -e "ms('1',1)" "NCC(O)=O"

[NH3+]CC([O-])=O

$ evaluate -e "ms('1',2)" "NCC(O)=O"

NCC(O)=O

$ evaluate -e "ms('1',3)" "NCC(O)=O"

NCC([O-])=O

$ evaluate -e "msDistr('1',0)" "NCC(O)=O"

95.3

$ evaluate -e "msDistr('1',1)" "NCC(O)=O"

4.7

$ evaluate -e "msDistr('1',2)" "NCC(O)=O"

0

$ evaluate -e "msDistr('1',3)" "NCC(O)=O"

0

Best regards,

Zsolt

User 677b9c22ff

17-11-2006 06:55:01

Hi,

yes. Thanks alot, I was thinking about a range, so I will try one of the other terms you suggested.

Tobias