modify line for spin_cubic, spin_none. edit docs a bit.

doc/src/min_modify.txt

@@ -84,12 +84,12 @@ The choice of a line search algorithm for the {spin_oso_cg} and
 {spin_oso_lbfgs} styles can be specified via the {line} keyword.
 The {spin_cubic} and  {spin_none} only make sense 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.
+The {spin_cubic} performs the line search based on a cubic interpolation
+of the energy along the search direction. The {spin_none} keyword
+deactivates the line search procedure.
+The {spin_none} is a default value for {line} keyword apart from the case when
+single-replica calculations are performed with {spin_oso_lbfgs} that
+uses {spin_cubic} line search.
 
 [Restrictions:] The line search procedure of styles
 {spin_oso_cg} and {spin_oso_lbfgs} cannot be used for magnetic

doc/src/min_spin.txt

@@ -18,7 +18,7 @@ min_style spin_oso_lbfgs :pre
 [Examples:]
 
 min_style 	spin_oso_lbfgs 
-min_modify      discrete_factor 10.0 line spin_none :pre 
+min_modify      line spin_none discrete_factor 10.0 :pre
 
 [Description:]
 
@@ -55,12 +55,21 @@ 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}. 
+discretization factor {discrete_factor}.
+By defualt, the style {spin_oso_cg} does not employ line search procedure and
+and uses the adaptive time-step technique in the same way as style {spin}.
 
 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.
+(L-BFGS) algorithm.
+By default, style {spin_oso_lbfgs} uses a line search procedure
+based on cubic interpolation for
+a single-replica calculation, and it does not use line search procedure
+for a multireplica calculation (such as in case of GNEB calculation).
+If the line search procedure is not used then the discrete factor defines
+the maximum root mean squared rotation angle of spins by equation {pi/(5*Kappa)}.
+The default value for Kappa is 10.
+
 The "min_modify"_min_modify.html command can be used to
 deactivate the line search procedure, and to modify the
 discretization factor {discrete_factor}. 

doc/src/minimize.txt

@@ -106,10 +106,10 @@ the number of total force evaluations exceeds {maxeval} :ul
 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 
-spins and their precession vectors omega) is less than {ftol}, 
-or if any of the other criteria are met.
+The minimization procedure stops if the 2-norm (length) of the torque vector on atom
+(defined as the cross product between the
+atomic spin and its precession vectors omega) is less than {ftol},
+or if any of the other criteria are met. Torque have the same units as the energy.
 
 NOTE: You can also use the "fix halt"_fix_halt.html command to specify
 a general criterion for exiting a minimization, that is a calculation

doc/src/neb_spin.txt

@@ -59,7 +59,7 @@ performance speed-up you would see with one or more physical
 processors per replica.  See the "Howto replica"_Howto_replica.html
 doc page for further discussion.
 
-NOTE: As explained below, a GNEB calculation performs a damped dynamics
+NOTE: As explained below, a GNEB calculation performs a
 minimization across all the replicas. One of the "spin"_min_spin.html
 style minimizers has to be defined in your input script. 
 
@@ -170,8 +170,8 @@ command is issued.
 :line
 
 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
+minimization procedure.  To enable
+this, you must first define a
 "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).