ChargeCalculator:FAQ: Difference between revisions
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Why | Why are the charges different? | ||
Explain charge definitions, QM reference data and EEM parameters... | |||
How do I choose the best parameter set? | |||
Discussion above plus what to do with charges... | |||
How do I add parameters if they do not exist? | |||
Explain structure of the xml file; | |||
Explain how to approximate parameters (e.g., based on electronegaitivity) | |||
Add procedure, copy/paste. | |||
Can I combine parameter sets if I have a biomacromolecule which binds a drug like molecule? | |||
Not really necessary (the parameters for biomolecules seem good enough). Explain how to use chemical elements efficiently. | |||
Can I get good electrostatic potentials? | |||
Some papers report such. Also, some charges better than others... | |||
Can I get dipole moments? | |||
In general, no. The concept of atomic charges has its limitations. Dipoles and higher order multipoles are known to be poorly approximated by a point charge model. You may try though... maybe to compare the dipoles of derivatives of the same molecule... | |||
'''Start by having a look at the main [[ChargeCalculator:Terminology | terms]] used by ACC, or return to the [[ChargeCalculator:UserManual | Table of contents]].''' | |||
Revision as of 07:02, 24 December 2014
Why are the charges different? Explain charge definitions, QM reference data and EEM parameters...
How do I choose the best parameter set? Discussion above plus what to do with charges...
How do I add parameters if they do not exist? Explain structure of the xml file; Explain how to approximate parameters (e.g., based on electronegaitivity) Add procedure, copy/paste.
Can I combine parameter sets if I have a biomacromolecule which binds a drug like molecule? Not really necessary (the parameters for biomolecules seem good enough). Explain how to use chemical elements efficiently.
Can I get good electrostatic potentials? Some papers report such. Also, some charges better than others...
Can I get dipole moments? In general, no. The concept of atomic charges has its limitations. Dipoles and higher order multipoles are known to be poorly approximated by a point charge model. You may try though... maybe to compare the dipoles of derivatives of the same molecule...
Start by having a look at the main terms used by ACC, or return to the Table of contents.