+/** Interface to level1 nonbonded AdResS kernels.
+ *
+ * The parameters are the same as for \ref nb_kernel_t except for the last, so
+ * please consult its documentation as well.
+ *
+ * \param nri Number of neighborlists/i-particles/outer-particles.
+ * The outer loop of the nonbonded kernel will iterate
+ * over these indices. This number must always
+ * be provided,
+ * \param iinr Atom number (starting on 0) for each index 0..(nri-1)
+ * in the outer loop. These are the 'owner'/'parent'
+ * particles of each neighborlist. It is quite common
+ * that a particle occurs several times with different
+ * shift indices. This is the field 'ilist' in
+ * the neighborlist. This array must always be provided.
+ * \param jindex This array specifies the index of the first j neighbor
+ * in the array jjnr[] which belongs to the corresponding
+ * i atom. The j neighbors for all lists are merged into
+ * one continous array, so we also get the first index for
+ * the next list in the next element. The size of this list
+ * is nri+1, and the last position contains the number of
+ * entries in the j list. Confused? It is actually pretty
+ * straightforward; for index <tt>i</tt> the i atom is
+ * <tt>iinr[i]</tt>, and the atom indices of the neighbors
+ * to interact with are in positions <tt>jindex[i]</tt>
+ * through <tt>(jindex[i+1]-1)</tt> in <tt>jjnr[]</tt>.
+ * This corresponds to ilist_jindex in the neighborlist.
+ * This array must always be provided.
+ * \param jjnr Array with the j particle neighbors of list i in positions
+ * <tt>jindex[i]</tt> through <tt>(jindex[i+1]-1)</tt>. This
+ * field is called jlist in the neighborlist structure.
+ * This array must always be provided.
+ * \param shift Array with shift vector index corresponding to each
+ * iinr neighborlist. In most codes, periodic boundary
+ * conditions are applied by checking pairwise distances
+ * of particles, and correcting differences of more than
+ * half a box. This is costly (latencies) and unnecessary
+ * since we already decided which periodic copy to use during
+ * neighborsearching. We solve this by introducing
+ * \a shiftvectors and a \a shiftindex. The shiftvectors is
+ * normally an array of 3*3*3 vectors, corresponding to
+ * displacements +- one box unit in one or more directions.
+ * The central box (no displacement) is always in the middle,
+ * index 13 in the case of 3*3*3 shift vectors.
+ * Imagine a particle interacting with two particles in the
+ * current box, and three particles in the box to the left.
+ * We represent this with two ilist entries, one with shift
+ * index=13 (central box) and one with shift index=12.
+ * all neighbors in each sublist will have the same shift,
+ * so in the nonbonded interaction, we only have to add the
+ * shift vector to the outer (i) particle coordinates before
+ * starting the loop over neighbors. This extracts periodic
+ * boundary condition calculations from the inner loops,
+ * increasing performance significantly. This array must
+ * always be provided, but if you do not use any periodic
+ * boundary conditions you could set all elements to zero
+ * and provide a shiftvec array of length three, with all
+ * elements there too being zero.
+ * \param shiftvec The shift vectors for each index. Since the code needs to
+ * interface with Fortran or assembly, we have to use
+ * pointers to float/double instead of the gmx_rvec_t type.
+ * The x/y/z shift distances for shift index idx are in
+ * <tt>shiftvec[3*idx]</tt>, <tt>shiftvec[3*idx+1]</tt>,
+ * and <tt>shiftvec[3*idx+2]</tt>. This is fully binary
+ * compatible with an array of gmx_rvec_t, so you can simply
+ * use a typecast when calling. The length of the array is
+ * three times the number of shift indices. This array
+ * must be provided, but see the comment for shift.
+ * \param fshift Forces from 'other periodic boxes' for each shift index.
+ * The shift concept does not affect the forces on individual
+ * atoms, but it will have an effect on the virial. To
+ * account for this, we add the total force on the i particle
+ * in each outer loop to the current shift index in this
+ * array, which has exactly the same dimensions as the
+ * shiftvec array above. The Gromacs manual describes how
+ * this is used to calculate the effect in the virial.
+ * Dimension is identical to shiftvec.
+ * For kernels that do not calculate forces this can be NULL.
+ * \param gid Energy group index for each i neighborlist index; this
+ * corresponds to ilist_groupindex in the neighborlist and is
+ * used to decompose energies into groupwise contributions.
+ * If an i particle belongs to group A, and has interactions
+ * both with groups A,B, and C, you will get three different
+ * i list entries with energy group indices corresponding to
+ * A-A, A-B, and A-C neighbors, in addition to possible
+ * copies due to different shift indices. The energies will
+ * be added to this index (i.e. index=gid[i]) in the vc and
+ * vnb arrays. This array must always be provided.
+ * If you don't want to decompose energies all groups should
+ * be set to index 0 (length or the array nri).
+ * \param pos Coordinates of atoms, starting on 0 as all arrays. To
+ * interface with fortran and assembly this is a simple list
+ * of floats, with x/y/z of atom n in positions
+ * <tt>pos[3*n]</tt>, <tt>pos[3*n+1]</tt>, and
+ * <tt>pos[3*n+2]</tt>. This is binary compatible with,
+ * and can be typecast from, an array of gmx_rvec_t.
+ * This array must always be provided.
+ * \param faction Forces of atoms. To interface with fortran and assembly
+ * this is a simple list of floats, with x/y/z of atom n in
+ * positions <tt>pos[3*n]</tt>, <tt>pos[3*n+1]</tt>, and
+ * <tt>pos[3*n+2]</tt>. This is binary compatible with,
+ * and can be typecast from, an array of gmx_rvec_t.
+ * For kernels that do not calculate forces this can be NULL.
+ * \param charge Array with the charge of atom n in position n.
+ * If you are calling a kernel without coulomb interaction
+ * this parameter can safely be set to NULL.
+ * \param facel Factor to multiply all electrostatic interactions with;
+ * this is essentially 1/(4*pi*epsilon). For kernels without
+ * coulomb interaction the value will not be used. In the
+ * fortran version (pass-by-reference) it can be NULL in
+ * that case.
+ * \param krf The 'k' constant for reaction-field electrostatic
+ * interactions. Can be zero/NULL for non-RF interactions.
+ * \param crf The 'c' constant for reaction-field electrostatic
+ * interactions. Can be zero/NULL for non-RF interactions.
+ * \param vc List of Coulomb energies, the length is equal to the
+ * number of energy group combinations. As described for
+ * gid above, the coulomb energy of each outer/i-particle
+ * list will be added to vc[gid[i]]. Can be NULL for
+ * kernels without electrostatic interaction.
+ * \param type Array with the index of the Van der Waals type for each
+ * atom, starting on 0 . This is used to look up the VdW
+ * parameters. When no VdW interactions are calculated
+ * (i.e. only Coulomb), this can be set to NULL.
+ * \param ntype Number of VdW types, used to look up the VdW parameters.
+ * This parameter can be zero (NULL for pass-by-reference)
+ * if the kernel does not include VdW interactions.
+ * \param vdwparam Array with Van der Waals parameters. The contents and
+ * size depends on the number of parameters required for
+ * the selected VdW interaction (3 for B-ham, 2 for LJ, etc).
+ * There are a total of ntype*ntype pair combinations, and
+ * the size of this array is the number of such pairs times
+ * the number of parameters.
+ * With 'nparam' parameters, and 'ntype' types in total,
+ * the first parameter for interactions between atoms of VdW
+ * type 'ti' and VdW type 'tj' is located in
+ * <tt>vdwparam[nparam*(ntype*ti+tj)]</tt>, and the
+ * additional parameters follow directly in the next
+ * position(s). Note that the array corresponds to a
+ * symmetric matrix - you should get the same parameters if
+ * you swap ti and tj. This parameter can be NULL
+ * if the kernel does not include VdW interactions.
+ * \param vvdw List of Van der Waals energies, the length is equal to
+ * the number of energy group combinations. As described
+ * for gid above, the coulomb energy of each outer list
+ * will be added to vc[gid[i]]. Can be NULL for
+ * kernels without electrostatic interaction.
+ * \param tabscale Distance between table points in the vftab table.
+ * This is always the same for Coulomb and VdW when both
+ * are tabulated. If the kernel does not include any
+ * tabulated interactions it can be zero, or NULL when
+ * passed-by-reference.
+ * \param vftab Table data for Coulomb and/or VdW interactions.
+ * Each 'point' in the table consists of the four
+ * floating-point numbers Y,F,G,H as described in the
+ * Gromacs manual. If the kernel only tabulates the
+ * Coulomb interaction this is followed by the next
+ * point. If both Coulomb and Van der Waals interactions
+ * are tabulated it is instead followed by another
+ * four numbers for the dispersion table at the same
+ * point, and then finally the repulsion table, i.e.
+ * a total of 12 numbers per table point. If only
+ * Van der Waals interactions are tabulated the
+ * Dispersion and Repulsion table (in that order) use
+ * a total of 8 floating-point numbers per point.
+ * This array only needs to be provided for kernels with
+ * tabulated interactions - otherwise it can be NULL.
+ * \param invsqrta Array with the inverse square root of the born radius
+ * of each atom. This can safely be NULL when the kernel
+ * does not calculate Generalized Born interactions.
+ * \param dvda Array where the derivative of the potential with respect
+ * to the born radius for each atom will be written. This
+ * is necessary to calculate the effect of born radius
+ * derivatives on forces. However, just as for the force
+ * arrays it must be provided even when not calculating
+ * forces, since an implementation might not provide a
+ * non-force version of the routine. When the kernel does
+ * not calculate Generalized Born interactions it can
+ * safely be set to NULL, though.
+ * \param gbtabscale Distance between (scaled) table points for tabulated
+ * Generalized Born interactions. If the kernel does not
+ * calculate Generalized Born interactions it can be zero,
+ * or NULL when passed-by-reference. Note that this is
+ * usually different from the standard (non-GB) table scale.
+ * \param gbtab Table data for Generalized Born Coulomb interactions.
+ * Since these interactions contain parameters that
+ * enter in a non-trivial way I have introduced a trick
+ * where the tabulated interaction is a function of
+ * the distance scaled with the square roots of the two
+ * born radii. Apart from this it contains similar
+ * data (Y,F,G,H) as the normal Coulomb/VdW tables.
+ * See comments in the table code for details. This
+ * can safely be set to NULL if you are not using
+ * Generalized Born interactions.
+ * \param nthreads Number of threads calling the kernel concurrently.
+ * This value is only used to optimize the chunk size
+ * of the neighborlists processed by each thread, so
+ * it won't cause incorrect results if you get it wrong.
+ * \param count Pointer to a common counter to synchronize
+ * multithreaded execution. This is normally the counter
+ * in the neighborlist. It must be set to zero before
+ * calling the kernel to get correct results. Note that
+ * this is necessary even for a single thread if Gromacs
+ * is compiled with thread support (meaning it is
+ * a mandatory parameter).
+ * \param mtx Pointer to a mutex protecting the counter, masked as
+ * a pointer-to-void since thread support is optional.
+ * However, if Gromacs is compiled with threads you \a must
+ * provide a mutex - it would hurt performance to check
+ * it for each iteration in the nonbonded kernel. The
+ * mutex is normally created automatically by the
+ * neighborlist initialization routine gmx_nlist_init().
+ * (Yet another reason not to call kernels directly).
+ * \param outeriter The number of iterations performed in the outer loop
+ * of the kernel will be written to this integer. If
+ * multiple threads are calling the loop this will be
+ * the part of nri handled by this thread.
+ * This value is only used to get accurate flop accounting.
+ * Since we cannot check for NULL pointers in Fortran it must
+ * always be provided, but you can discard
+ * the result if you don't need it.
+ * \param inneriter The number of iterations performed in the inner loop
+ * of the kernel will be written to this integer; compare
+ * with nouter. Since we cannot check for NULL pointers in
+ * Fortran it must always be provided, but you can discard
+ * the result if you don't need it.
+ * \param work Double precision work array - to be used for optimization.
+ * \param[in] wf Array with the AdResS weight function of the atom n in
+ * position n.
+ *
+ * \warning There is \a very little error control inside
+ * the nonbonded kernels in order to maximize performance.
+ * It cannot be overemphasized that you should never call
+ * them directly, but rely on the higher-level routines.
+ */
typedef void
nb_adress_kernel_t(int * nri,
int * iinr,
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