About MMAPS

Alloy Theoretic Automated Toolkit (ATAT)
1

Hi, this is incheol.
Thanks for providing this amazing tool, Professor Axel van de Walle and developers.

I am currently working on investigating a system with mmaps where A,B are residing in the same lattice.
And I got 3 questions .

  1. The results by commanding "mapsrep" do not agree with concentration contraint that I set in crange.in.
    I set "0.24<A<0.26" in crange.in but the results are positioned at A=0.33 (only "predicted" and "known str" were shown)

Even though the directories for calculations are generated, there were various kinds of concentration of A.(maybe they are for initial ECI fitting) and no structures are saved in gs_str.out and predstr.out
Therefore, I want to know whether the way I set crange.in is wrong or the setting is OK but I need specifications for plotting the data.

  1. How the MMAPS generate a structure before predicting its energy? just randomly?

3.I want to save structures generated by mmaps even though they are not turned out to be ground state structures. Is there a way to do so?

I’ll appreciate it if you spare me some time for these questions.
Thanks in advance.

2
  1. (m)maps generates structures outside the specified range to check if the ground state(s) in the specified composition range might have a tie-line with ground states outside of the range. This is important to know.

2 . read https://dx.doi.org/10.1361/105497102770331596 Section 3.2

  1. You generate all structure up to a certain cell size with the separate code genstr (also in ATAT).
3

Thanks for the reply, Professor.

I got more questions about concentration constraint.

Followings are the input files

"lat.in"
x1 y1 z1 A,B
x2 y2 z2 A,B
x3 y3 z3 A,B
x4 y4 z4 A,B
x5 y5 z5 A,B
x6 y6 z6 A,B
x7 y7 z7 A,B
x8 y8 z8 A,B
x9 y9 z9 C
x10 y10 z10 C
x11 y11 z11 C
x12 y12 z12 C

"crange.in"
0.2<1.0*B<0.3

I am specifically interested in A=0.75, B=0.25
However, output of mmaps only shows structures at x=0.33 which is out of 0.2~0.3

Therefore,

Q1. I want to know whether the statement in crange.in is correctly expressed.

Concentration in predstr.out shows 0.3333 xxxxx yyyyy for every lines while x and y varies.
Q2. Why does it have three components for concentration rather than two for A and B?
Q3. What is the order of those three components? A,B,C?

Thanks in advance.

4

The syntax of the crange.in file is more limited: you can only have one inequality per expression.
BTW, your lat.in is missing 6 lines defining the axes and the lattice vectors…

mmaps lists all composition even those that are constant.

The file atoms.out gives the order in which the compositions are listed.