PSATD: current correction works only with global FFTs (#1131)

* Clean up implementation of current correction:

- abort when current correction runs with psatd.periodic_single_box_fft=0
- rename input parameter from psatd.do_current_correction to psatd.current_correction
- add nodal tests in 2D and 3D (using direct current deposition)
- change 2D test: use Esirkepov deposition, instead of direct, as in 3D test
- add/update relevant checksum benchmarks

* Small clean-up

1 files changed, 9 insertions, 14 deletions

diff --git a/Source/Evolve/WarpXEvolve.cpp b/Source/Evolve/WarpXEvolve.cpp
index 72621e52c..d53c5ea5b 100644
--- a/Source/Evolve/WarpXEvolve.cpp
+++ b/Source/Evolve/WarpXEvolve.cpp
@@ -288,14 +288,13 @@ WarpX::OneStep_nosub (Real cur_time)
     if (warpx_py_afterdeposition) warpx_py_afterdeposition();
 #endif
 
+// TODO
+// Apply current correction in Fourier space: for domain decomposition with local
+// FFTs over guard cells, apply this before calling SyncCurrent
 #ifdef WARPX_USE_PSATD
-    // Apply current correction in Fourier space
-    // (equation (19) of https://doi.org/10.1016/j.jcp.2013.03.010)
-    if ( fft_periodic_single_box == false ) {
-        // For domain decomposition with local FFT over guard cells,
-        // apply this before `SyncCurrent`, i.e. before exchanging guard cells for J
-        if ( do_current_correction ) CurrentCorrection();
-    }
+    if ( !fft_periodic_single_box && current_correction )
+        amrex::Abort("\nCurrent correction does not guarantee charge conservation with local FFTs over guard cells:\n"
+                     "set psatd.periodic_single_box_fft=1 too, in order to guarantee charge conservation");
 #endif
 
 #ifdef WARPX_QED
@@ -306,14 +305,10 @@ WarpX::OneStep_nosub (Real cur_time)
     SyncCurrent();
     SyncRho();
 
+// Apply current correction in Fourier space: for periodic single-box global FFTs
+// without guard cells, apply this after calling SyncCurrent
 #ifdef WARPX_USE_PSATD
-    // Apply current correction in Fourier space
-    // (equation (19) of https://doi.org/10.1016/j.jcp.2013.03.010)
-    if ( fft_periodic_single_box == true ) {
-        // For periodic, single-box FFT (FFT without guard cells)
-        // apply this after `SyncCurrent`, i.e. after exchanging guard cells for J
-        if ( do_current_correction ) CurrentCorrection();
-    }
+    if ( fft_periodic_single_box && current_correction ) CurrentCorrection();
 #endif