Enable support for Tetragonal {e.g. 123} spacegroups

Signed-off-by: Wolfgang Ludwig <wolfgang.ludwig@esrf.fr>

zUtil_Cryst/gtCrystGetSymmetryOperators.m

@@ -36,6 +36,8 @@ if (~exist('crystal_system', 'var') || isempty(crystal_system))
             crystal_system = 'hexagonal';
         elseif between(spacegroup, 143, 167)
             crystal_system = 'trigonal';
+        elseif between(spacegroup, 75, 142)
+            crystal_system = 'tetragonal';
         else
             gtError('gtCrystGetSymmetryOperators:wrong_input', [ ...
                 'Unimplemented spacegroup (' num2str(spacegroup) ')!']);
@@ -164,6 +166,48 @@ switch (crystal_system)
             0  0 -1 ;...
             0 -1  0 ];
 
+    case 'tetragonal'
+        if exist('spacegroup', 'var') && ~isempty(spacegroup)
+            if ~between(spacegroup, 75, 142)
+                gtError('gtCrystGetSymmetryOperators:wrong_input', [ ...
+                    'spacegroup (' num2str(spacegroup) ') does not ' ...
+                    'match with the crystal system (' crystal_system ')!']);
+            end
+        end
+
+        % Diamond software
+        symm(1).g3  = [ 1  0  0 ;...
+            0  1  0 ;...
+            0  0  1 ];
+
+        symm(2).g3  = [ 0 -1  0 ;...
+            1  0  0 ;...
+            0  0  1 ];
+
+        symm(3).g3  = [-1  0  0 ;...
+            0 -1  0 ;...
+            0  0  1 ];
+
+        symm(4).g3  = [ 0  1  0 ;...
+           -1  0  0 ;...
+            0  0  1 ];
+
+        symm(5).g3  = [ 1  0  0 ;...
+            0 -1  0 ;...
+            0  0 -1 ];
+
+        symm(6).g3  = [-1  0  0 ;...
+            0  1  0 ;...
+            0  0 -1 ];
+
+        symm(7).g3  = [ 0  1  0 ;...
+            1  0  0 ;...
+            0  0 -1 ];
+
+        symm(8).g3  = [ 0 -1  0 ;...
+           -1  0  0 ;...
+            0  0 -1 ];
+
     case 'hexagonal'
         if exist('spacegroup', 'var') && ~isempty(spacegroup)
             if ~between(spacegroup, 168, 194) && spacegroup ~= 663

zUtil_Cryst/gtCrystRodriguesFundZone.m

@@ -75,7 +75,24 @@ switch spacegroup
 		% All faces
 		faces = [basal; facets];
         
-        
+    % Tetragonal
+	case {123}
+
+		% Bottom and top of the polyhedron (basal planes):
+		limbase = sqrt(2)-1;  % half thickness along basal plane
+		basal = [ 0  0  1  0  0  1;
+			      0  0 -1  0  0 -1]*(limbase+sm);
+
+		% Facets on the side:
+		limfacet = 1;         % extension laterally
+		t = (0:(pi/4):2*pi)';
+		t = t(1:end-1);
+		facets = [cos(t) sin(t) zeros(8,1)]*(limfacet+sm);
+		facets = [facets, facets];
+
+		% All faces
+		faces = [basal; facets];
+
 	% Orthorhombic and unknown (limit to 90deg rotations in all direction)
 	case {0, 62}    
 		

zUtil_Cryst/gtFindFamilies.m

@@ -31,6 +31,9 @@ if any(strcmp(parameters.cryst(phaseID).crystal_system, {'hexagonal', 'trigonal'
 elseif strcmp(parameters.cryst(phaseID).crystal_system, 'cubic')
     % sort hkl - h,k,l all equivilent
     test=sort(hkl,2);
+elseif strcmp(parameters.cryst(phaseID).crystal_system, 'tetragonal')
+    % so far only tested for the output delivered from diamond software (already sorted...) 
+    test = hkl;
 else
     error('Need to add crystal system "%s" to gtFindFamiles.m ... quitting', parameters.cryst(phaseID).crystal_system)
 end