diff -Nru votca-xtp-1.6.3/CHANGELOG.md votca-xtp-1.6.4/CHANGELOG.md
--- votca-xtp-1.6.3/CHANGELOG.md	2020-12-09 03:54:05.000000000 +0000
+++ votca-xtp-1.6.4/CHANGELOG.md	2021-01-12 18:26:43.000000000 +0000
@@ -1,6 +1,10 @@
 For more detailed information about the changes see the history of the
 [repository](https://github.com/votca/xtp/commits/master).
 
+## Version 1.6.4 (released 12.01.21)
+* fix build on openSUSE (#622)
+* Refactored logger (#625)
+
 ## Version 1.6.3 (released 09.12.20)
 * switch to ghcr.io for CI (#555)
 * fixing Gaussian guess read keyword (#562, #563)
diff -Nru votca-xtp-1.6.3/CMakeLists.txt votca-xtp-1.6.4/CMakeLists.txt
--- votca-xtp-1.6.3/CMakeLists.txt	2020-12-09 03:54:05.000000000 +0000
+++ votca-xtp-1.6.4/CMakeLists.txt	2021-01-12 18:26:43.000000000 +0000
@@ -2,7 +2,7 @@
 project(votca-xtp)
 
 
-set(PROJECT_VERSION "1.6.3")
+set(PROJECT_VERSION "1.6.4")
 set(PROJECT_CONTACT "bugs@votca.org")
 string(REGEX REPLACE "^[1-9]+\\.([1-9]+).*$" "\\1" SOVERSION "${PROJECT_VERSION}")
 if (NOT ${SOVERSION} MATCHES "[1-9]+")
diff -Nru votca-xtp-1.6.3/debian/changelog votca-xtp-1.6.4/debian/changelog
--- votca-xtp-1.6.3/debian/changelog	2020-12-13 18:59:37.000000000 +0000
+++ votca-xtp-1.6.4/debian/changelog	2021-01-29 05:45:40.000000000 +0000
@@ -1,3 +1,9 @@
+votca-xtp (1.6.4-1) unstable; urgency=medium
+
+  * New upstream release.
+
+ -- Nicholas Breen <nbreen@debian.org>  Thu, 28 Jan 2021 21:45:40 -0800
+
 votca-xtp (1.6.3-1) unstable; urgency=medium
 
   * New upstream release.
diff -Nru votca-xtp-1.6.3/debian/control votca-xtp-1.6.4/debian/control
--- votca-xtp-1.6.3/debian/control	2020-12-13 18:59:37.000000000 +0000
+++ votca-xtp-1.6.4/debian/control	2021-01-29 05:43:58.000000000 +0000
@@ -18,9 +18,9 @@
                libfftw3-dev,
                libhdf5-dev,
                libsqlite3-dev,
-               libvotca-csg-dev (>= 1.6.3),
+               libvotca-csg-dev (>= 1.6.4),
                libvotca-csg-dev (<< 1.7~),
-               libvotca-tools-dev (>= 1.6.3),
+               libvotca-tools-dev (>= 1.6.4),
                libvotca-tools-dev (<< 1.7~),
                libxc-dev,
                pkg-config,
diff -Nru votca-xtp-1.6.3/include/votca/xtp/logger.h votca-xtp-1.6.4/include/votca/xtp/logger.h
--- votca-xtp-1.6.3/include/votca/xtp/logger.h	2020-12-09 03:54:05.000000000 +0000
+++ votca-xtp-1.6.4/include/votca/xtp/logger.h	2021-01-12 18:26:43.000000000 +0000
@@ -42,7 +42,7 @@
 /*
  * Custom buffer to store messages
  */
-class LogBuffer : public std::stringbuf {
+class LogBuffer final : public std::stringbuf {
 
  public:
   LogBuffer() : std::stringbuf() { _LogLevel = Log::current_level; }
@@ -105,7 +105,7 @@
   bool _writePreface = true;
 
  protected:
-  int sync() override {
+  int sync() {
 
     std::ostringstream _message;
 
@@ -165,35 +165,30 @@
   }
 
  public:
-  Logger() : std::ostream(new LogBuffer()), _ReportLevel(Log::current_level) {
+  Logger() : std::ostream(&_buffer), _ReportLevel(Log::current_level) {
     setMultithreading(_maverick);
   }
   Logger(Log::Level ReportLevel)
-      : std::ostream(new LogBuffer()), _ReportLevel(ReportLevel) {
+      : std::ostream(&_buffer), _ReportLevel(ReportLevel) {
     setMultithreading(_maverick);
   }
 
-  ~Logger() final {
-    delete rdbuf();
-    rdbuf(nullptr);
-  }
-
   Logger &operator()(Log::Level LogLevel) {
-    dynamic_cast<LogBuffer *>(rdbuf())->setLogLevel(LogLevel);
+    _buffer.setLogLevel(LogLevel);
     return *this;
   }
 
   void setReportLevel(Log::Level ReportLevel) { _ReportLevel = ReportLevel; }
   void setMultithreading(bool maverick) {
     _maverick = maverick;
-    dynamic_cast<LogBuffer *>(rdbuf())->setMultithreading(_maverick);
+    _buffer.setMultithreading(_maverick);
   }
   bool isMaverick() const { return _maverick; }
 
   Log::Level getReportLevel() const { return _ReportLevel; }
 
   void setPreface(Log::Level level, const std::string &preface) {
-    dynamic_cast<LogBuffer *>(rdbuf())->setPreface(level, preface);
+    _buffer.setPreface(level, preface);
   }
 
   void setCommonPreface(const std::string &preface) {
@@ -203,22 +198,19 @@
     setPreface(Log::warning, preface);
   }
 
-  void EnablePreface() { dynamic_cast<LogBuffer *>(rdbuf())->EnablePreface(); }
+  void EnablePreface() { _buffer.EnablePreface(); }
 
-  void DisablePreface() {
-    dynamic_cast<LogBuffer *>(rdbuf())->DisablePreface();
-  }
+  void DisablePreface() { _buffer.DisablePreface(); }
 
  private:
+  LogBuffer _buffer;
   // at what level of detail output messages
   Log::Level _ReportLevel = Log::error;
 
   // if true, only a single processor job is executed
   bool _maverick = false;
 
-  std::string Messages() {
-    return dynamic_cast<LogBuffer *>(rdbuf())->Messages();
-  }
+  std::string Messages() { return _buffer.Messages(); }
 };
 
 /**
diff -Nru votca-xtp-1.6.3/src/libxtp/dftengine/dftengine.cc votca-xtp-1.6.4/src/libxtp/dftengine/dftengine.cc
--- votca-xtp-1.6.3/src/libxtp/dftengine/dftengine.cc	2020-12-09 03:54:05.000000000 +0000
+++ votca-xtp-1.6.4/src/libxtp/dftengine/dftengine.cc	2021-01-12 18:26:43.000000000 +0000
@@ -23,6 +23,7 @@
 #include "votca/xtp/qmmolecule.h"
 #include <boost/filesystem.hpp>
 #include <boost/format.hpp>
+#include <iomanip>
 #include <vector>
 #include <votca/tools/constants.h>
 #include <votca/tools/elements.h>
diff -Nru votca-xtp-1.6.3/src/libxtp/polarregion.cc votca-xtp-1.6.4/src/libxtp/polarregion.cc
--- votca-xtp-1.6.3/src/libxtp/polarregion.cc	2020-12-09 03:54:05.000000000 +0000
+++ votca-xtp-1.6.4/src/libxtp/polarregion.cc	2021-01-12 18:26:43.000000000 +0000
@@ -18,6 +18,7 @@
  */
 
 #include "votca/xtp/eeinteractor.h"
+#include <iomanip>
 #include <numeric>
 #include <votca/xtp/dipoledipoleinteraction.h>
 #include <votca/xtp/polarregion.h>
diff -Nru votca-xtp-1.6.3/src/libxtp/qmpackages/nwchem.cc votca-xtp-1.6.4/src/libxtp/qmpackages/nwchem.cc
--- votca-xtp-1.6.3/src/libxtp/qmpackages/nwchem.cc	2020-12-09 03:54:05.000000000 +0000
+++ votca-xtp-1.6.4/src/libxtp/qmpackages/nwchem.cc	2021-01-12 18:26:43.000000000 +0000
@@ -21,6 +21,7 @@
 #include <boost/algorithm/string.hpp>
 #include <boost/filesystem.hpp>
 #include <boost/format.hpp>
+#include <iomanip>
 #include <votca/tools/filesystem.h>
 #include <votca/tools/getline.h>
 #include <votca/xtp/ecpaobasis.h>
diff -Nru votca-xtp-1.6.3/src/libxtp/tools/apdft.cc votca-xtp-1.6.4/src/libxtp/tools/apdft.cc
--- votca-xtp-1.6.3/src/libxtp/tools/apdft.cc	2020-12-09 03:54:05.000000000 +0000
+++ votca-xtp-1.6.4/src/libxtp/tools/apdft.cc	2021-01-12 18:26:43.000000000 +0000
@@ -16,6 +16,7 @@
  */
 
 #include "apdft.h"
+#include <iomanip>
 #include <votca/xtp/density_integration.h>
 #include <votca/xtp/orbitals.h>
 #include <votca/xtp/vxc_grid.h>
diff -Nru votca-xtp-1.6.3/tutorials/CMakeLists.txt votca-xtp-1.6.4/tutorials/CMakeLists.txt
--- votca-xtp-1.6.3/tutorials/CMakeLists.txt	2020-12-09 03:54:05.000000000 +0000
+++ votca-xtp-1.6.4/tutorials/CMakeLists.txt	2021-01-12 18:26:44.000000000 +0000
@@ -2,7 +2,7 @@
 
 project(xtp-tutorials)
 
-set(PROJECT_VERSION "1.6.3")
+set(PROJECT_VERSION "1.6.4")
 
 set(CMAKE_MODULE_PATH ${CMAKE_CURRENT_SOURCE_DIR}/CMakeModules)
 include(GNUInstallDirs)