Question on the meaning of maxind

[st3107]

Hello, @aglie . I am a new user of meerkat. I have a question on the meaning of "maxind".

For example, maxind = [4, 5, 6] is the reconstruction h=-4...4, k=-5...5, l=-6...6. Then, how is the (h, k, l) defined? A point at (h, k, l) in the reciprocal space is corresponded to a vector 1/wavelength * (h, k, l) or (a * h, b * k, c * l) in the reciprocal space? (a, b, c) are reciprocal lattice constants of the crystal.

[aglie]

Hi Songsheng,
Great to hear there is a new user in Meerkat!

the meaning of maxind

As you correctly pointed out maxind defines the reconstruction limits in reciprocal space. Meerkat always reconstructs symmetric region, so minimal indices will negative of the maximum indices.

For example, maxind = [4, 5, 6] is the reconstruction h=-4...4, k=-5...5, l=-6...6

Absolutely correct

Then, how is the (h, k, l) defined?

I am using crystallographic notation here, so everything is defined with respect to the reciprocal lattice of your crystal, this means in general

where s is the position of a scattering vector in reciprocal space, a*, b* and c* are reciprocal basis vectors of your crystal, and h, k and l - reciprocal fractional coordinates. Note that in general a*, b* and c* are not perpendicular to each other, but in case they are (like in the case of cubic, tetragonal or orthorombic crystals) then your formula number two is correct: