Commit JT 072319

- added 2 oso examples in examples/SPIN/spinmin
- added doc for oso_cg and oso_lbfgs

doc/src/lammps.book

@@ -647,6 +647,7 @@ pair_sph_lj.html
 pair_sph_rhosum.html
 pair_sph_taitwater.html
 pair_sph_taitwater_morris.html
+pair_spin_dipole.html
 pair_spin_dmi.html
 pair_spin_exchange.html
 pair_spin_magelec.html

doc/src/min_modify.txt

@@ -13,11 +13,11 @@ min_modify command :h3
 min_modify keyword values ... :pre
 
 one or more keyword/value pairs may be listed :ulb,l
-keyword = {dmax} or {line} or {alpha_damp} or {discrete_factor}
+keyword = {dmax} or {line} or {alpha_damp} or {discrete_factor} or {spin_cubic} or {spin_none}
   {dmax} value = max
     max = maximum distance for line search to move (distance units)
-  {line} value = {backtrack} or {quadratic} or {forcezero}
+  {line} value = {backtrack} or {quadratic} or {forcezero} or {spin_cubic} or {spin_none}
-    backtrack,quadratic,forcezero = style of linesearch to use 
+    backtrack,quadratic,forcezero,spin_cubic,spin_none = style of linesearch to use 
   {alpha_damp} value = damping
     damping = fictitious Gilbert damping for spin minimization (adim)
   {discrete_factor} value = factor
@@ -80,7 +80,21 @@ See "min_spin"_min_spin.html for more information about those
 quantities. 
 Default values are {alpha_damp} = 1.0 and {discrete_factor} = 10.0.
 
-[Restrictions:] none
+The choice of a line search algorithm for the {spin_oso_cg} and
+{spin_oso_lbfgs} can be specified via the {line} keyword.
+The {spin_cubic} and  {spin_none} only make sense when those two
+when one of those two minimization styles is declared.
+
+The {spin_cubic} keyword activates the line search procedure when 
+the {spin_oso_cg} algorithm is used.
+
+The {spin_none} keyword deactivates the line search procedure when 
+the {spin_oso_lbfgs} algorithm is used.
+
+[Restrictions:] The line search procedure of styles
+{spin_oso_cg} and {spin_oso_lbfgs} cannot be used for magnetic
+NEB calculations. See "neb/spin"_neb_spin.html for more
+explanation.
 
 [Related commands:]
 

doc/src/min_spin.txt

@@ -6,14 +6,19 @@
 :line
 
 min_style spin command :h3
+min_style spin_oso_cg command :h3
+min_style spin_oso_lbfgs command :h3
 
 [Syntax:]
 
-min_style spin :pre
+min_style spin 
+min_style spin_oso_cg 
+min_style spin_oso_lbfgs :pre
 
 [Examples:]
 
-min_style 	spin :pre 
+min_style 	spin_oso_lbfgs 
+min_modify      discrete_factor 10.0 line_search 0 :pre 
 
 [Description:]
 
@@ -46,9 +51,29 @@ definition of this timestep.
 {discrete_factor} can be defined with the "min_modify"_min_modify.html
 command.
 
-NOTE: The {spin} style replaces the force tolerance by a torque
+Style {spin_oso_cg} defines an orthogonal spin optimization
+(OSO) combined to a conjugate gradient (CG) algorithm. 
+The "min_modify"_min_modify.html command can be used to
+couple the {spin_oso_cg} to a line search procedure, and to modify the 
+discretization factor {discrete_factor}. 
+
+Style {spin_oso_lbfgs} defines an orthogonal spin optimization
+(OSO) combined to a limited-memory Broyden-Fletcher-Goldfarb-Shanno 
+(LBFGS) algorithm. 
+By default, style {spin_oso_lbfgs} uses a line search procedure.
+The "min_modify"_min_modify.html command can be used to
+deactivate the line search procedure. 
+
+For more information about styles {spin_oso_cg} and {spin_oso_lbfgs}, 
+see their implementation reported in "(Ivanov)"_#Ivanov1.
+
+NOTE: All the {spin} styles replace the force tolerance by a torque
 tolerance. See "minimize"_minimize.html for more explanation. 
 
+NOTE: The {spin_oso_cg} and {spin_oso_lbfgs} styles can be used
+for magnetic NEB calculations only if the line search procedure
+is deactivated. See "neb/spin"_neb_spin.html for more explanation. 
+
 [Restrictions:] 
 
 This minimization procedure is only applied to spin degrees of
@@ -63,3 +88,8 @@ freedom for a frozen lattice configuration.
 
 The option defaults are {alpha_damp} = 1.0 and {discrete_factor} =
 10.0.
+
+:line
+
+:link(Ivanov1)
+[(Ivanov)] Ivanov, Uzdin, Jonsson. arXiv preprint arXiv:1904.02669, (2019).

doc/src/min_style.txt

@@ -11,7 +11,8 @@ min_style command :h3
 
 min_style style :pre
 
-style = {cg} or {hftn} or {sd} or {quickmin} or {fire} or {spin} :ul
+style = {cg} or {hftn} or {sd} or {quickmin} or {fire} or {spin}
+or {spin_oso_cg} or {spin_oso_lbfgs} :ul
 
 [Examples:]
 
@@ -64,11 +65,25 @@ a minimization.
 
 Style {spin} is a damped spin dynamics with an adaptive 
 timestep.
-See the "min/spin"_min_spin.html doc page for more information.
+
+Style {spin_oso_cg} uses an orthogonal spin optimization (OSO)
+combined to a conjugate gradient (CG) approach to minimize spin
+configurations. 
+
+Style {spin_oso_lbfgs} uses an orthogonal spin optimization (OSO)
+combined to a limited-memory Broyden-Fletcher-Goldfarb-Shanno
+(LBFGS) approach to minimize spin configurations. 
+
+See the "min/spin"_min_spin.html doc page for more information
+about the {spin}, {spin_oso_cg} and {spin_oso_lbfgs} styles.
 
 Either the {quickmin} and {fire} styles are useful in the context of
 nudged elastic band (NEB) calculations via the "neb"_neb.html command.
 
+Either the {spin}, {spin_oso_cg} and {spin_oso_lbfgs} styles are useful 
+in the context of magnetic geodesic nudged elastic band (GNEB) calculations 
+via the "neb/spin"_neb_spin.html command.
+
 NOTE: The damped dynamic minimizers use whatever timestep you have
 defined via the "timestep"_timestep.html command.  Often they will
 converge more quickly if you use a timestep about 10x larger than you

doc/src/minimize.txt

@@ -103,7 +103,8 @@ the line search fails because the step distance backtracks to 0.0
 the number of outer iterations or timesteps exceeds {maxiter}
 the number of total force evaluations exceeds {maxeval} :ul
 
-NOTE: the "minimization style"_min_style.html {spin} replaces
+NOTE: the "minimization style"_min_style.html {spin},
+{spin_oso_cg}, and {spin_oso_lbfgs} replace
 the force tolerance {ftol} by a torque tolerance.
 The minimization procedure stops if the 2-norm (length) of the 
 global torque vector (defined as the cross product between the 

doc/src/neb_spin.txt

@@ -172,7 +172,8 @@ command is issued.
 A NEB calculation proceeds in two stages, each of which is a
 minimization procedure, performed via damped dynamics.  To enable
 this, you must first define a damped spin dynamics
-"min_style"_min_style.html, using the {spin} style (see
+"min_style"_min_style.html, using either the {spin},
+{spin_oso_cg}, or {spin_oso_lbfgs} style (see
 "min_spin"_min_spin.html for more information).  
 The other styles cannot be used, since they relax the lattice
 degrees of freedom instead of the spins.
@@ -358,6 +359,9 @@ This command can only be used if LAMMPS was built with the SPIN
 package.  See the "Build package"_Build_package.html doc
 page for more info.
 
+The line search procedures of the {spin_oso_cg} and {spin_oso_lbfgs} 
+minimization styles cannot be used in a GNEB calculation. 
+
 :line
 
 [Related commands:]

doc/src/pair_spin_dipole.txt

@@ -25,9 +25,8 @@ pair_coeff * * 10.0
 pair_coeff 2 3 8.0 :pre
 
 pair_style spin/dipole/long 9.0
-pair_coeff * * 1.0 1.0
+pair_coeff * * 10.0
-pair_coeff 2 3 1.0 1.0 2.5 4.0 scale 0.5
+pair_coeff 2 3 6.0 :pre
-pair_coeff 2 3 1.0 1.0 2.5 4.0 :pre
 
 [Description:]
 

examples/SPIN/spinmin/in.spinmin_cg.bfo

@@ -0,0 +1,54 @@
+# bfo in a 3d periodic box
+
+units 		metal
+dimension 	3
+boundary 	p p f
+atom_style 	spin
+
+# necessary for the serial algorithm (sametag)
+atom_modify 	map array 
+
+lattice 	sc 3.96
+region 		box block 0.0 34.0 0.0 34.0 0.0 1.0
+create_box 	1 box
+create_atoms 	1 box
+
+# setting mass, mag. moments, and interactions for bcc iron
+
+mass		1 1.0
+set 		group all spin/random 11 2.50
+
+pair_style 	hybrid/overlay spin/exchange 6.0 spin/magelec 4.5 spin/dmi 4.5
+pair_coeff 	* * spin/exchange exchange 6.0 -0.01575 0.0 1.965
+# pair_coeff 	* * spin/magelec magelec 4.5 0.000109 1.0 1.0 1.0
+pair_coeff 	* * spin/magelec magelec 4.5 0.00109 1.0 1.0 1.0
+pair_coeff 	* * spin/dmi dmi 4.5 0.00005 1.0 1.0 1.0
+
+neighbor 	0.1 bin
+neigh_modify 	every 10 check yes delay 20
+
+fix 		1 all precession/spin anisotropy 0.0000033 0.0 0.0 1.0
+fix_modify	1 energy yes
+
+timestep	0.0001
+
+compute 	out_mag    all spin
+compute 	out_pe     all pe
+compute 	out_ke     all ke
+compute 	out_temp   all temp
+
+variable 	magz      equal c_out_mag[3]
+variable 	magnorm   equal c_out_mag[4]
+variable 	emag      equal c_out_mag[5]
+variable 	tmag      equal c_out_mag[6]
+
+thermo          50
+thermo_style    custom step time v_magnorm v_emag v_tmag temp etotal
+thermo_modify   format float %20.15g
+
+compute 	outsp all property/atom spx spy spz sp fmx fmy fmz
+dump 		1 all custom 50 dump.lammpstrj type x y z c_outsp[1] c_outsp[2] c_outsp[3] c_outsp[4] c_outsp[5] c_outsp[6] c_outsp[7]
+
+min_style	spin/oso_cg
+min_modify 	discrete_factor 10.0 line_search 0
+minimize        1.0e-10 1.0e-10 10000 1000

examples/SPIN/spinmin/in.spinmin_lbfgs.bfo

@@ -0,0 +1,54 @@
+# bfo in a 3d periodic box
+
+units 		metal
+dimension 	3
+boundary 	p p f
+atom_style 	spin
+
+# necessary for the serial algorithm (sametag)
+atom_modify 	map array 
+
+lattice 	sc 3.96
+region 		box block 0.0 34.0 0.0 34.0 0.0 1.0
+create_box 	1 box
+create_atoms 	1 box
+
+# setting mass, mag. moments, and interactions for bcc iron
+
+mass		1 1.0
+set 		group all spin/random 11 2.50
+
+pair_style 	hybrid/overlay spin/exchange 6.0 spin/magelec 4.5 spin/dmi 4.5
+pair_coeff 	* * spin/exchange exchange 6.0 -0.01575 0.0 1.965
+#pair_coeff 	* * spin/magelec magelec 4.5 0.000109 1.0 1.0 1.0
+pair_coeff 	* * spin/magelec magelec 4.5 0.00109 1.0 1.0 1.0
+pair_coeff 	* * spin/dmi dmi 4.5 0.00005 1.0 1.0 1.0
+
+neighbor 	0.1 bin
+neigh_modify 	every 10 check yes delay 20
+
+fix 		1 all precession/spin anisotropy 0.0000033 0.0 0.0 1.0
+fix_modify	1 energy yes
+
+timestep	0.0001
+
+compute 	out_mag    all spin
+compute 	out_pe     all pe
+compute 	out_ke     all ke
+compute 	out_temp   all temp
+
+variable 	magz      equal c_out_mag[3]
+variable 	magnorm   equal c_out_mag[4]
+variable 	emag      equal c_out_mag[5]
+variable 	tmag      equal c_out_mag[6]
+
+thermo          50
+thermo_style    custom step time v_magnorm v_emag v_tmag temp etotal
+thermo_modify   format float %20.15g
+
+compute 	outsp all property/atom spx spy spz sp fmx fmy fmz
+dump 		1 all custom 50 dump.lammpstrj type x y z c_outsp[1] c_outsp[2] c_outsp[3] c_outsp[4] c_outsp[5] c_outsp[6] c_outsp[7]
+
+min_style	spin/oso_lbfgs
+min_modify 	discrete_factor 10.0 line_search 1
+minimize        1.0e-15 1.0e-10 10000 1000

src/SPIN/min_spin.cpp

@@ -80,12 +80,12 @@ void MinSpin::setup_style()
 int MinSpin::modify_param(int narg, char **arg)
 {
   if (strcmp(arg[0],"alpha_damp") == 0) {
-    if (narg < 2) error->all(FLERR,"Illegal fix_modify command");
+    if (narg < 2) error->all(FLERR,"Illegal min_modify command");
     alpha_damp = force->numeric(FLERR,arg[1]);
     return 2;
   }
   if (strcmp(arg[0],"discrete_factor") == 0) {
-    if (narg < 2) error->all(FLERR,"Illegal fix_modify command");
+    if (narg < 2) error->all(FLERR,"Illegal min_modify command");
     discrete_factor = force->numeric(FLERR,arg[1]);
     return 2;
   }

src/SPIN/min_spin_oso_cg.cpp

@@ -133,12 +133,10 @@ void MinSpinOSO_CG::setup_style()
 int MinSpinOSO_CG::modify_param(int narg, char **arg)
 {
   if (strcmp(arg[0],"line_search") == 0) {
-    if (narg < 2) error->all(FLERR,"Illegal fix_modify command");
+    if (narg < 2) error->all(FLERR,"Illegal min_modify command");
     use_line_search = force->numeric(FLERR,arg[1]);
-
     if (nreplica > 1 && use_line_search)
       error->all(FLERR,"Illegal fix_modify command, cannot use NEB and line search together");
-
     return 2;
   }
   if (strcmp(arg[0],"discrete_factor") == 0) {
@@ -250,9 +248,9 @@ int MinSpinOSO_CG::iterate(int maxiter)
       neval++;
     }
 
-    //// energy tolerance criterion
+    // energy tolerance criterion
-    //// only check after DELAYSTEP elapsed since velocties reset to 0
+    // only check after DELAYSTEP elapsed since velocties reset to 0
-    //// sync across replicas if running multi-replica minimization
+    // sync across replicas if running multi-replica minimization
   
     if (update->etol > 0.0 && ntimestep-last_negative > DELAYSTEP) {
       if (update->multireplica == 0) {

src/SPIN/min_spin_oso_lbfgs.cpp

@@ -145,16 +145,14 @@ int MinSpinOSO_LBFGS::modify_param(int narg, char **arg)
 {
 
   if (strcmp(arg[0],"line_search") == 0) {
-    if (narg < 2) error->all(FLERR,"Illegal fix_modify command");
+    if (narg < 2) error->all(FLERR,"Illegal min_modify command");
     use_line_search = force->numeric(FLERR,arg[1]);
-
     if (nreplica > 1 && use_line_search)
-      error->all(FLERR,"Illegal fix_modify command, cannot use NEB and line search together");
+      error->all(FLERR,"Illegal min_modify command, cannot use NEB and line search together");
-
     return 2;
   }
   if (strcmp(arg[0],"discrete_factor") == 0) {
-    if (narg < 2) error->all(FLERR,"Illegal fix_modify command");
+    if (narg < 2) error->all(FLERR,"Illegal min_modify command");
     double discrete_factor;
     discrete_factor = force->numeric(FLERR,arg[1]);
     maxepsrot = MY_2PI / (10 * discrete_factor);
@@ -266,9 +264,9 @@ int MinSpinOSO_LBFGS::iterate(int maxiter)
       neval++;
     }
 
-    //// energy tolerance criterion
+    // energy tolerance criterion
-    //// only check after DELAYSTEP elapsed since velocties reset to 0
+    // only check after DELAYSTEP elapsed since velocties reset to 0
-    //// sync across replicas if running multi-replica minimization
+    // sync across replicas if running multi-replica minimization
   
     if (update->etol > 0.0 && ntimestep-last_negative > DELAYSTEP) {
       if (update->multireplica == 0) {