## 6.2.1.1. SELECTING BRAVAIS LATTICES

next, previous Section / Table of Contents / Index Option [K] selected from the lattice option menu L, see Sec. 6.2.1, allows you to define any of the 14 primitive Bravais lattices. This lattice can be updated later to include a lattice basis for the most general definition of a non-primitive lattice, see Sec. 6.2.1.2. The Bravais lattice menu LK reads ========== LATTICE OPTIONS =============================================== Select from Bravais lattices : [A] triclinic-P [B] monoclinic-P [C] monoclinic-B [D] rhombic-P [E] rhombic-C [F] rhombic-I [G] rhombic-F [H] tetragonal-P [I] tetragonal-I [J] hexagonal-P [K] trigonal-R [L] cubic-P [M] cubic-I [N] cubic-F [?,]esc ==================================================================== 79 == > [A] selected from submenu LK confirms a primitive triclinic lattice, see Sec. 5.3, and prompts for three lattice constants, a, b, c, by triclinic-P lattice selected, code = 10 Basic lattice constants A,B,C : and for three angles, <(R2,R3), <(R1,R3), <(R1,R2), by Angles <(R2,R3), <(R1,R3), <(R1,R2) : which concludes the lattice definition. > [B] selected from submenu LK confirms a primitive monoclinic lattice, see Sec. 5.3, and prompts for three lattice constants, a, b, c, by monoclinic-P lattice selected, code = 10 Basic lattice constants A,B,C : and for three angles, <(R2,R3), <(R1,R3), <(R1,R2), with constraints Angles <(R2,R3), <(R1,R3), <(R1,R2) ( alp,90,90 / 90,bet,90 / 90,90,gam ): where in all three cases, see Sec. 5.3, two of the angles must equal 90 degrees, which concludes the lattice definition. > [C] selected from submenu LK confirms a side centered monoclinic lattice, see Sec. 5.3, and prompts for three lattice constants, a, b, c, by monoclinic-C lattice selected, code = 10 Basic lattice constants A,B,C : and for three angles, <(R2,R3), <(R1,R3), <(R1,R2), with constraints Angles <(R2,R3), <(R1,R3), <(R1,R2) ( alp,90,90 / 90,bet,90 / 90,90,gam ): where in all three cases, see Sec. 5.3, two of the angles must equal 90 degrees, which concludes the lattice definition. > [D] selected from submenu LK confirms a primitive orthorhombic lattice, see Sec. 5.3, and prompts for three lattice constants, a, b, c, by orthorhombic-P lattice selected, code = 10 Basic lattice constants A,B,C : which concludes the lattice definition. > [E] selected from submenu LK confirms a side centered orthorhombic lattice, see Sec. 5.3, and prompts for three lattice constants, a, b, c, by orthorhombic-C lattice selected, code = 10 Basic lattice constants A,B,C : which concludes the lattice definition. > [F] selected from submenu LK confirms a body centered orthorhombic lattice, see Sec. 5.3, and prompts for three lattice constants, a, b, c, by orthorhombic-I lattice selected, code = 10 Basic lattice constants A,B,C : which concludes the lattice definition. > [G] selected from submenu LK confirms a face centered orthorhombic lattice, see Sec. 5.3, and prompts for three lattice constants, a, b, c, by orthorhombic-F lattice selected, code = 10 Basic lattice constants A,B,C : which concludes the lattice definition. > [H] selected from submenu LK confirms a primitive tetragonal lattice, see Sec. 5.3, and prompts for two lattice constants, a, c, by tetragonal-P lattice selected, code = 10 Basic lattice constants A,C : which concludes the lattice definition. > [I] selected from submenu LK confirms a body centered tetragonal lattice, see Sec. 5.3, and prompts for two lattice constants, a, c, by tetragonal-I lattice selected, code = 10 Basic lattice constants A,C : which concludes the lattice definition. > [J] selected from submenu LK confirms a primitive hexagonal lattice, see Sec. 5.3, and prompts for two lattice constants, a, c, by hexagonal-P lattice selected, code = 10 Basic lattice constants A,C : which concludes the lattice definition. > [K] selected from submenu LK confirms a trigonal rhombic lattice, see Sec. 5.3, and prompts for one lattice constant, a, by trigonal-R lattice selected, code = 10 Basic lattice constants A : and for one angle, <(R1,R2), by Angle <(R1,R2) : which concludes the lattice definition. > [L] selected from submenu LK confirms a primitive cubic lattice, see Sec. 5.3, and prompts for one lattice constant, a, by cubic-P lattice selected, code = 10 Basic lattice constants A : which concludes the lattice definition. > [M] selected from submenu LK confirms a body centered cubic lattice, see Sec. 5.3, and prompts for one lattice constant, a, by cubic-I lattice selected, code = 10 Basic lattice constants A : which concludes the lattice definition. > [N] selected from submenu LK confirms a face centered cubic lattice, see Sec. 5.3, and prompts for one lattice constant, a, by cubic-I lattice selected, code = 10 Basic lattice constants A : which concludes the lattice definition. > [,] selected from submenu LK returns to the lattice option menu L if the lattice is built from scratch or else moves to the BALSAC/LATTICE main option menu, see Sec. 6.2.0. The selection of a Bravais lattice is followed by a prompt Global lattice scaling constant a= asking for a global lattice constant a to scale all lattice vectors (a = 1.0 yields no scaling). This completes the lattice definition and BALSAC/LATTICE moves to the Miller index option (main option [M]) if the lattice section is built from scratch or returns to the BALSAC/LATTICE main option menu, see Sec. 6.2.0. next, previous Section / Table of Contents / Index