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39 #include "nbnxm_geometry.h"
41 #include "gromacs/nbnxm/nbnxm.h"
42 #include "gromacs/utility/fatalerror.h"
43 #include "gromacs/utility/real.h"
47 /* Clusters at the cut-off only increase rlist by 60% of their size */
48 static constexpr real c_nbnxnRlistIncreaseOutsideFactor = 0.6;
50 real nbnxn_get_rlist_effective_inc(const int jClusterSize, const real atomDensity)
52 /* We should get this from the setup, but currently it's the same for
53 * all setups, including GPUs.
55 const real iClusterSize = c_nbnxnCpuIClusterSize;
57 const real iVolumeIncrease = (iClusterSize - 1) / atomDensity;
58 const real jVolumeIncrease = (jClusterSize - 1) / atomDensity;
60 return c_nbnxnRlistIncreaseOutsideFactor * std::cbrt(iVolumeIncrease + jVolumeIncrease);
63 real nbnxn_get_rlist_effective_inc(const int clusterSize, const gmx::RVec& averageClusterBoundingBox)
65 /* The average length of the diagonal of a sub cell */
66 const real diagonal = std::sqrt(norm2(averageClusterBoundingBox));
68 const real volumeRatio = (clusterSize - 1.0_real) / clusterSize;
70 return c_nbnxnRlistIncreaseOutsideFactor * gmx::square(volumeRatio) * 0.5_real * diagonal;