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

                  ATOMS - the positions of four atoms that define spatial extent of 
                          the cavity. For more information on how to specify lists of 
                          atoms see \ref Group 

The following arguments are compulsory: 

                   DATA - The multicolvar that calculates the set of base quantities 
                          that we are interested in 
                  SIGMA - the width of the function to be used for kernel density 
                          estimation 
                 KERNEL - ( default=gaussian ) the type of kernel function to be used 

In addition you may use the following options: 

  NUMERICAL_DERIVATIVES - ( default=off ) calculate the derivatives for these 
                          quantities numerically 
                  NOPBC - ( default=off ) ignore the periodic boundary conditions 
                          when calculating distances 
                 SERIAL - ( default=off ) do the calculation in serial. Do not use 
                          MPI 
                 LOWMEM - ( default=off ) lower the memory requirements 
                TIMINGS - ( default=off ) output information on the timings of the 
                          various parts of the calculation 
                OUTSIDE - ( default=off ) calculate quantities for colvars that are 
                          on atoms outside the region of interest 
              PRINT_BOX - ( default=off ) write out the positions of the corners of 
                          the box to an xyz file 
                   MEAN - take the mean of these variables. The final value can be 
                          referenced using <em>label</em>.mean. You can use multiple instances 
                          of this keyword i.e. MEAN1, MEAN2, MEAN3... The corresponding 
                          values are then referenced using <em>label</em>.mean-1, 
                          <em>label</em>.mean-2, <em>label</em>.mean-3... 
              LESS_THAN - calculate the number of variables less than a certain 
                          target value. 
              MORE_THAN - calculate the number of variables more than a certain 
                          target value. 
                BETWEEN - calculate the number of values that are within a certain 
                          range. These quantities are calculated using kernel density 
                          estimation as described on \ref histogrambead. The final value can be 
                          referenced using <em>label</em>.between. You can use multiple 
                          instances of this keyword i.e. BETWEEN1, BETWEEN2, BETWEEN3... The 
                          corresponding values are then referenced using <em>label</em>.between-1, 
                          <em>label</em>.between-2, <em>label</em>.between-3... 
              HISTOGRAM - calculate how many of the values fall in each of the bins 
                          of a histogram. This shortcut allows you to calculates NBIN 
                          quantities like BETWEEN. The final value can be referenced using 
                          <em>label</em>.histogram. You can use multiple instances of this keyword i.e. 
                          HISTOGRAM1, HISTOGRAM2, HISTOGRAM3... The corresponding values are then 
                          referenced using <em>label</em>.histogram-1, 
                          <em>label</em>.histogram-2, <em>label</em>.histogram-3... 
                    SUM - calculate the sum of all the quantities. The final value 
                          can be referenced using <em>label</em>.sum. You can use 
                          multiple instances of this keyword i.e. SUM1, SUM2, SUM3... The 
                          corresponding values are then referenced using <em>label</em>.sum-1, 
                          <em>label</em>.sum-2, <em>label</em>.sum-3... 
                   FILE - the file on which to write out the box coordinates 
                  UNITS - ( default=nm ) the units in which to write out the corners 
                          of the box 


