# Umbrella Sampling/ PMF

Dear users

Could anybody introduce an illustrative text for concept of
Umbrella Sampling and Potential of Mean Force.

What is the physical meaning underlying those?
How are they calculated?

Bests

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Dear users

Could anybody introduce an illustrative text for concept of
*Umbrella Sampling* and *Potential of Mean Force*.

What is the physical meaning underlying those?
How are they calculated?

​i think this is a discussion that you should have with your
besides: ​http://lmgtfy.com/?q=umbrella+sampling+molecular+dynamics

...and if you've been a nice person, you might ask santa's little helpers
to have him stuff something like this into your stockings:

​axel.​

Thanks, Axel.

But, I’ve already searched web thoroughly. All discussions are short and vague.

I’m seeking for anything like a lecture or movie, suitable for simply learning concept of PMF and Umbrella Sampling

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Thanks, Axel.

But, I've already searched web thoroughly. All discussions are short and
vague.

​if they are too short and too vague for you, you have to get a text book.​
there should be introductions in any text book on MD that is worth having.
if that is not sufficient, you can look at chris chipot's book and/or the
many, many articles published on various methods and review articles
comparing methods or benchmarking methods for managing statistical errors.

I'm seeking for anything like a lecture or movie, suitable for simply
learning concept of PMF and Umbrella Sampling

the basic concepts of a PMF or Umbrella sampling *are* quite simple.

concept 1) since you get a force​ as the derivative of the potential, it is
just logical, that integrating the force with respect to a given coordinate
will give you a potential.
concept 2) to improve sampling across the selected coordinate (or
collective variable) you apply a biasing force, e.g. a position restraint

​there isn't really much to it unless you are lacking a require
understanding of statistical mechanics fundamentals.

besides. in my experience online media like recorded lectures and ​alike
are rarely effective. working your way through examples and reproducing
results and then modifying them and understanding the changes in results is
the most effective way to learn and understand. there is no replacement for
getting your hands dirty, making mistakes, learning from them and
consulting (in person) with experienced colleagues.

​axel.​