chemical reaction from the point of view of quantum mechanics

[alkis3]

Hi all

sorry for my bad English.

I want to write a program of computer modeling of chemical reactions.

The program should calculate the interaction of nuclei and electrons , based on these calculations to simulate chemical reactions.

This requires detailed information about in reality how chemical reactions occur from the point of view of quantum mechanics

Please advise books dealing with questions or give a link to information or share something about this.

[John Cuthber]

Do you have any idea how difficult that problem is?

You need a supercomputer, even for fairly simple systems.

[alkis3]

I guess it's hard

but I want to try and I need some information

[studiot]

 

The program should calculate the interaction of nuclei and electrons

 

 

Chemical reactions do not, in general, involve nuclei.

I assume you mean the nuclei of atoms.

 

Nuclear reactions involve atomic nuclei.

 

Are you referring to the chemical terms electrophilic reactions and nucleophilic reactions?

[John Cuthber]

Studiot,

The difference between dimethyl ether and ethanol is where the nuclei are.

You do need to consider the interactions of the nuclei- they have almost all the mass so they strongly affect the way things react.

 

Then there are the effects of nuclear spin

http://en.wikipedia.org/wiki/Spin_isomers_of_hydrogen

though those are normally very small.

 

alkis3

 

if you want to do the calculations, the only data you need are the masses and charges of the electrons and nuclei.

Good luck- you will need it.

[alkis3]

I was referring to the interaction of Atomic nucleus and electrons

 

 

The problem is that I don't know why to calculate it is a big challenge?

a chemical reaction occurs under the influence of a small number of forces

1-interaction with electric charges ,2 - the spin of the electron

....and probably all interaction is based only on interaction with electric charges

why to calculate just 1 power or 2-3 forces so hard?

[John Cuthber]

Because you need to know where the electrons are to calculate the forces

the uncertainty principle tells you that you can't know where they are

the electrons- wherever they are- also affect each other.

 

Have a look at the "many body problem"

[studiot]

 

Have a look at the "many body problem"

 

 

 

Gosh didn't I mention that somewhere else recently?

 

JC, I am only trying to help clarify alkis3's questions since he genuinely wants to achieve something.

[alkis3]

that is, the problem is that it is not known where the electron is

and this assumes that the electron anywhere

and it is necessary to calculate all the possible places?

[Sensei]

 

Chemical reactions do not, in general, involve nuclei.

I assume you mean the nuclei of atoms.

 

Mouse or rats die after week of drinking heavy water.

 

Heavy water D₂O, HDO, have just one or two neutrons in Hydrogen more than normal not harmful water..

[John Cuthber]

that is, the problem is that it is not known where the electron is

and this assumes that the electron anywhere

and it is necessary to calculate all the possible places?

Yes, you need to average the effect of the other electrons using an average weighted by the probability of the electron being in a particular place.

That distribution depends on all the other electrons.

[alkis3]

 

Mouse or rats die after week of drinking heavy water.

what is the reason?

[studiot]

Why not pick a particular chemical reaction and work on that to start with, before trying for a more all embracing theory?

 

My Questions have been designed to elucidate information for anybody to try to help.

I wish to avoid an argument about what actually participates in chemical reactions so I said "in general".

I am sure there are always the famous exceptions.

 

This is because of the stated objective of the thread.

 

I still maintain that the principal players are the electrons. - in general.

 

I am still not sure what exactly you are trying to calculate and from what starting point?

 

By this I mean what are your proposed input variables and output variables?

 

An electron has potential energy due to the potential field it finds itself in. This field is generated by the presence of the nucleus or nuclei.

 

If there is to be a an unforced reconfiguration (which is what a chemical reaction is) then it will be energetically feasible if the end configuration has lower PE than the initial one.

 

So it seems sensible to proceed by studying the calculation of these energies.

 

For this a good starting point might be the book by Atkins and Friedman

 

Molecular Quantum Mechanics

[Sensei]

what is the reason?

 

Search for "rats" in this article:

http://en.wikipedia.org/wiki/Heavy_water

Section "Effect on animals"

 

I noticed something interesting:

 

"An early experiment[10] reported not the "slightest difference" in taste between ordinary and heavy water; on the other hand, rats given a choice between distilled normal water and heavy water were able to avoid the heavy water based on smell, and it may be possible that it has a different taste.[11]"

Edited April 2, 2014 by Sensei

[alkis3]

probably that is changing characteristics of inertia of such atoms

the change is very significant ,in 2 times

Edited April 2, 2014 by alkis3