function p = calcul_pts(beta)
%
p = zeros(12,3);
r = 1.0; s = 0.5;
c32 = sqrt(3)/2; sbeta = sin(beta); cbeta = cos(beta);
c3 = sqrt(3);
del = sqrt(1.0 - (0.75*sbeta*sbeta));
h = r*c32*cbeta*sbeta/del;
ta = 2*r*del;

p(1,1) = ta/c3 - s*sbeta; p(1,2) = 0; p(1,3) = s*cbeta + h/2;
p(2,1) = ta/c3 + s*sbeta; p(2,2) = 0; p(2,3) = -s*cbeta + h/2.0;
td = r/del; cosbl = sbeta/(2*del); sinbl = cbeta/del;
p(5,1) = td/c3 + s*sinbl; p(5,2) = 0; p(5,3) = s*cosbl - h/2;
p(6,1) = td/c3 - s*sinbl; p(6,2) = 0; p(6,3) = -s*cosbl - h/2;
p(3,:) = rotatez(p(5,:),pi/3);
p(4,:) = rotatez(p(6,:),pi/3);
p(5,:) = rotatez(p(1,:),2*pi/3);
p(6,:) = rotatez(p(2,:), 2*pi/3);
p(9,:) = rotatez(p(1,:), -2*pi/3);
p(10,:) = rotatez(p(2,:), -2*pi/3);
p(7,:) = rotatez(p(3,:), 2*pi/3);
p(8,:) = rotatez(p(4,:), 2*pi/3);
p(11,:) = rotatez(p(3,:), -2*pi/3);
p(12,:) = rotatez(p(4,:), -2*pi/3);
end
