Using Workbench Command

CREATE A BLANK VOLUME FILE
   wb_command -volume-create
      <i-dim> - length of first dimension
      <j-dim> - length of second dimension
      <k-dim> - length of third dimension
      <volume-out> - output - the output volume

      [-plumb] - set via axis order and spacing/offset
         <axis-order> - a string like 'XYZ' that specifies which index is along
            which spatial dimension
         <x-spacing> - change in x-coordinate from incrementing the relevant
            index
         <y-spacing> - change in y-coordinate from incrementing the relevant
            index
         <z-spacing> - change in z-coordinate from incrementing the relevant
            index
         <x-offset> - the x-coordinate of the center of the first voxel
         <y-offset> - the y-coordinate of the center of the first voxel
         <z-offset> - the z-coordinate of the center of the first voxel

      [-sform] - set via a nifti sform
         <xi-spacing> - increase in x coordinate from incrementing the i index
         <xj-spacing> - increase in x coordinate from incrementing the j index
         <xk-spacing> - increase in x coordinate from incrementing the k index
         <x-offset> - x coordinate of first voxel
         <yi-spacing> - increase in y coordinate from incrementing the i index
         <yj-spacing> - increase in y coordinate from incrementing the j index
         <yk-spacing> - increase in y coordinate from incrementing the k index
         <y-offset> - y coordinate of first voxel
         <zi-spacing> - increase in z coordinate from incrementing the i index
         <zj-spacing> - increase in z coordinate from incrementing the j index
         <zk-spacing> - increase in z coordinate from incrementing the k index
         <z-offset> - z coordinate of first voxel

      Creates a volume file full of zeros.  Exactly one of -plumb or -sform
      must be specified.