lc = 0.5;
//exterior
Point(1) =  {1, 1.73205, 0, lc};
Point(2) =  {-1, 1.73205, 0, lc};
Point(3) =  {-2, 0, 0, lc};
Point(4) =  {-1, -1.73205, 0, lc};
Point(5) =  {1, -1.73205, 0, lc};
Point(6) =  {2, 0, 0, lc};
Point(7) =  {1, 1.73205, 2, lc};
Point(8) =  {-1, 1.73205, 2, lc};
Point(9) =  {-2, 0, 2, lc};
Point(10) = {-1, -1.73205, 2, lc};
Point(11) = {1, -1.73205, 2, lc};
Point(12) = {2, 0, 2, lc};
//interior
Point(13) ={0.5, 0.8660254, 0, lc};
Point(14) ={-0.5, 0.8660254, 0, lc};
Point(15) ={-1, 0, 0, lc};
Point(16) ={-0.5, -0.8660254, 0, lc};
Point(17) ={0.5, -0.8660254, 0, lc};
Point(18) ={1, 0, 0, lc};
Point(19) ={0.5, 0.8660254, 2, lc};
Point(20) ={-0.5, 0.8660254, 2, lc};
Point(21) ={-1, 0, 2, lc};
Point(22) = {-0.5, -0.8660254, 2, lc};
Point(23) = {0.5, -0.8660254, 2, lc};
Point(24) = {1, 0, 2, lc};

//exterior bottom
Line(1) = {1, 2};
Line(2) = {2, 3};
Line(3) = {3, 4};
Line(4) = {4, 5};
Line(5) = {5, 6};
Line(6) = {6, 1};
//exterior top
Line(7) = {7, 8};
Line(8) = {8, 9};
Line(9) = {9, 10};
Line(10) = {10, 11};
Line(11) = {11, 12};
Line(12) = {12, 7};

//interior bottom
Line(13) = {14, 13};
Line(14) = {15, 14};
Line(15) = {16, 15};
Line(16) = {17, 16};
Line(17) = {18, 17};
Line(18) = {13, 18};
//interior top
Line(19) = {20, 19};
Line(20) = {21, 20};
Line(21) = {22, 21};
Line(22) = {23, 22};
Line(23) = {24, 23};
Line(24) = {19, 24};

//exterior wall
Line(25) = {1, 7};
Line(26) = {2, 8};
Line(27) = {3, 9};
Line(28) = {4, 10};
Line(29) = {5, 11};
Line(30) = {6, 12};
//interior wall
Line(31) = {13, 19};
Line(32) = {14, 20};
Line(33) = {15, 21};
Line(34) = {16, 22};
Line(35) = {17, 23};
Line(36) = {18, 24};

Line(37) = {3, 15};
Line(38) = {6, 18};
Line(39) = {9, 21};
Line(40) = {12, 24};

//bottom
Line Loop(1) = {1, 2, 37, 14, 13, 18, -38, 6};
Plane Surface(1) = {1};
Line Loop(2) = {3, 4, 5, 38, 17, 16, 15, -37};
Plane Surface(2) = {2};
//top
Line Loop(3) = {7, 8, 39, 20, 19, 24, -40, 12};
Plane Surface(3) = {3};
Line Loop(4) = {9, 10, 11, 40, 23, 22, 21, -39};
Plane Surface(4) = {4};
//exterior
Line Loop(5) = {1, 26, -7, -25};
Ruled Surface(5) = {5};
Line Loop(6) = {2, 27, -8, -26};
Ruled Surface(6) = {6};
Line Loop(7) = {3, 28, -9, -27};
Ruled Surface(7) = {7};
Line Loop(8) = {4, 29, -10, -28};
Ruled Surface(8) = {8};
Line Loop(9) = {5, 30, -11, -29};
Ruled Surface(9) = {9};
Line Loop(10) = {6, 25, -12, -30};
Ruled Surface(10) = {10};
//interior
Line Loop(11) = {-13, 32, 19, -31};
Ruled Surface(11) = {11};
Line Loop(12) = {-14, 33, 20, -32};
Ruled Surface(12) = {12};
Line Loop(13) = {-15, 34, 21, -33};
Ruled Surface(13) = {13};
Line Loop(14) = {-16, 35, 22, -34};
Ruled Surface(14) = {14};
Line Loop(15) = {-17, 36, 23, -35};
Ruled Surface(15) = {15};
Line Loop(16) = {-18, 31, 24, -36};
Ruled Surface(16) = {16};

Surface Loop(1) = {1,2,3,4,5,6,7,8,9,10,11,12,13,14,15,16};
Volume(1) = {1};
