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Short helpfile for action GYRATION_TENSOR
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The input trajectory can be in any of the following formats: 

                  ATOMS - the group of atoms that you are calculating the Gyration 
                          Tensor for. For more information on how to specify lists of atoms 
                          see \ref Group 

The following arguments are compulsory: 

                   TYPE - ( default=RADIUS ) The type of calculation relative to the 
                          Gyration Tensor you want to perform 

In addition you may use the following options: 

                  NOPBC - ( default=off ) ignore the periodic boundary conditions 
                          when calculating distances 
                 PHASES - ( default=off ) use trigonometric phases when computing 
                          position of center of mass 
                   MASS - ( default=off ) calculate the center of mass 
          MASS_WEIGHTED - ( default=off ) set the masses of all the atoms equal to 
                          one 
            UNORMALIZED - ( default=off ) do not divide by the sum of the weights 
                WEIGHTS - what weights should be used when calculating the center. If 
                          this keyword is not present the geometric center is computed. If 
                          WEIGHTS=@Masses is used the center of mass is computed. If WEIGHTS=@charges 
                          the center of charge is computed. If the label of an action is 
                          provided PLUMED assumes that that action calculates a list of 
                          symmetry functions that can be used as weights. Lastly, an explicit 
                          list of numbers to use as weights can be provided 


