Dear Fatima,
Unfortunately you've just
missed this year's Castep academic training workshop but in general if
you've paid for Accelrys support then you should be able to get help either
directly from them or the community fora. The "help" documentation for
Castep with Materials Studio isn't too bad either in my experience, it's
also fully searchable.
In general Castep help and tutorials can be obtained from
the webpage (
www.castep.org) and there's also the academic Castep support email list
(
https://www.jiscmail.ac.uk/cgi-bin/webadmin?A0=CASTEP) but be warned
that this is for Castep only not Materials Studio, so questions on the Materials
Studio interface will not usually be answered - Accelrys are paid to provide
this help!
You can also get Castep to give rudimentary help if you run
it from the command-line:
> castep.exe -help
<keyword>
where <keyword> is a Castep
parameter or cell keyword will cause Castep to tell you about <keyword>.
If you can't remember what the keyword is, just search for a relevant bit of
text, for example
> castep.exe -help search
optics
would get Castep to give you the name of
all keywords with "optics" in their name or brief
description.
I don't know Materials Studio very well, but I'll answer your
questions as best I can:
- From a crystal parameters
calculations how can I obtain the material properties of this crystal such as
the band gap.?
You need to run a band-structure or density-of-states (DOS)
calculation -- from memory I think these are found on the Properties tab -- then
plot ("View") the result to see the band gap. Make sure you do this
calculation as a continuation of your crystal geometry optimisation calculation
to ensure Castep picks up the optimised lattice constants.
- How to make a doping using
the material studio?
Select the atom you want to
change, then modify its element type either from the drop-down menus or
(possibly) by editing the appropriate value in Properties Explorer.
Alternatively just delete it and add the one you want at the same
location.
- How to obtain the optical
properties such as reflectivity, conductivity, dielectric constant
etc
I'm pretty sure these are accessible directly from the
Properties tab. You need to run an Optics calculation.
- What are the primitive cell,
super cell etc.
The primitive cell is the
smallest possible repeat unit. For example for a diamond structure the primitive
unit cell contains 2 atoms, with cell angles of 60 degrees. The primitive cell
is often not the conventional unit cell, e.g. the conventional diamond unit cell
contains 8 atoms and is cubic.
A supercell is just a simulation cell comprised of multiple unit
cells. For example if you're using the 8-atom conventional diamond cell, a
2x2x2 supercell would be twice as big in each dimension and contain 2x2x2x8 = 64
atoms.
Hope that helps,
Phil
Hasnip
(Castep developer)