diff --git a/src/classes/PTheory.cpp b/src/classes/PTheory.cpp
index 5bc21970..b41436f7 100644
--- a/src/classes/PTheory.cpp
+++ b/src/classes/PTheory.cpp
@@ -385,6 +385,10 @@ double PTheory::Func(register double t, const PDoubleVector& paramValues, const
           return DynamicGaussKTLF(t, paramValues, funcValues) * fMul->Func(t, paramValues, funcValues) +
                  fAdd->Func(t, paramValues, funcValues);
           break;
+        case THEORY_STATIC_LORENTZ_KT:
+          return StaticLorentzKT(t, paramValues, funcValues) * fMul->Func(t, paramValues, funcValues) +
+                 fAdd->Func(t, paramValues, funcValues);
+          break;
         case THEORY_STATIC_LORENTZ_KT_LF:
           return StaticLorentzKTLF(t, paramValues, funcValues) * fMul->Func(t, paramValues, funcValues) +
                  fAdd->Func(t, paramValues, funcValues);
@@ -465,6 +469,9 @@ double PTheory::Func(register double t, const PDoubleVector& paramValues, const
         case THEORY_DYNAMIC_GAUSS_KT_LF:
           return DynamicGaussKTLF(t, paramValues, funcValues) * fMul->Func(t, paramValues, funcValues);
           break;
+        case THEORY_STATIC_LORENTZ_KT:
+          return StaticLorentzKT(t, paramValues, funcValues) * fMul->Func(t, paramValues, funcValues);
+          break;
         case THEORY_STATIC_LORENTZ_KT_LF:
           return StaticLorentzKTLF(t, paramValues, funcValues) * fMul->Func(t, paramValues, funcValues);
           break;
@@ -534,6 +541,9 @@ double PTheory::Func(register double t, const PDoubleVector& paramValues, const
         case THEORY_DYNAMIC_GAUSS_KT_LF:
           return DynamicGaussKTLF(t, paramValues, funcValues) + fAdd->Func(t, paramValues, funcValues);
           break;
+        case THEORY_STATIC_LORENTZ_KT:
+          return StaticLorentzKT(t, paramValues, funcValues) + fAdd->Func(t, paramValues, funcValues);
+          break;
         case THEORY_STATIC_LORENTZ_KT_LF:
           return StaticLorentzKTLF(t, paramValues, funcValues) + fAdd->Func(t, paramValues, funcValues);
           break;
@@ -601,6 +611,9 @@ double PTheory::Func(register double t, const PDoubleVector& paramValues, const
         case THEORY_DYNAMIC_GAUSS_KT_LF:
           return DynamicGaussKTLF(t, paramValues, funcValues);
           break;
+        case THEORY_STATIC_LORENTZ_KT:
+          return StaticLorentzKT(t, paramValues, funcValues);
+          break;
         case THEORY_STATIC_LORENTZ_KT_LF:
           return StaticLorentzKTLF(t, paramValues, funcValues);
           break;
@@ -1156,6 +1169,39 @@ double PTheory::DynamicGaussKTLF(register double t, const PDoubleVector& paramVa
   return result;
 }
 
+//--------------------------------------------------------------------------
+/**
+ * <p> (see Uemura et al. PRB 31, 546 (85))
+ *
+ * \param t time in \f$(\mu\mathrm{s})\f$
+ * \param paramValues
+ */
+double PTheory::StaticLorentzKT(register double t, const PDoubleVector& paramValues, const PDoubleVector& funcValues) const
+{
+  // expected parameters: lambda [tshift]
+
+  double val[2];
+
+  assert(fParamNo.size() <= 2);
+
+  // check if FUNCTIONS are used
+  for (unsigned int i=0; i<fParamNo.size(); i++) {
+    if (fParamNo[i] < MSR_PARAM_FUN_OFFSET) { // parameter or resolved map
+      val[i] = paramValues[fParamNo[i]];
+    } else { // function
+      val[i] = funcValues[fParamNo[i]-MSR_PARAM_FUN_OFFSET];
+    }
+  }
+
+  double a_t;
+  if (fParamNo.size() == 1) // no tshift
+    a_t = t*val[0];
+  else // tshift present
+    a_t = (t-val[1])*val[0];
+
+  return 0.333333333333333 * (1.0 + 2.0*(1.0 - a_t)*TMath::Exp(-a_t));
+}
+
 //--------------------------------------------------------------------------
 /**
  * <p>
@@ -1446,11 +1492,11 @@ double PTheory::Abragam(register double t, const PDoubleVector& paramValues, con
  */
 double PTheory::InternalField(register double t, const PDoubleVector& paramValues, const PDoubleVector& funcValues) const
 {
-  // expected parameters: phase frequency rateT rateL [tshift]
+  // expected parameters: fraction phase frequency rateT rateL [tshift]
 
-  double val[5];
+  double val[6];
 
-  assert(fParamNo.size() <= 5);
+  assert(fParamNo.size() <= 6);
 
   // check if FUNCTIONS are used
   for (unsigned int i=0; i<fParamNo.size(); i++) {
@@ -1465,12 +1511,10 @@ double PTheory::InternalField(register double t, const PDoubleVector& paramValue
   if (fParamNo.size() == 4) // no tshift
     tt = t;
   else // tshift present
-    tt = t-val[4];
+    tt = t-val[5];
 
-  return 0.666666666666667*
-                 TMath::Cos(DEG_TO_RAD*val[0]+TWO_PI*val[1]*tt)*
-                 TMath::Exp(-val[2]*tt) +
-         0.333333333333333*TMath::Exp(-val[3]*tt);
+  return val[0]*TMath::Cos(DEG_TO_RAD*val[1]+TWO_PI*val[2]*tt)*TMath::Exp(-val[3]*tt) +
+         (1-val[0])*TMath::Exp(-val[4]*tt);
 }
 
 //--------------------------------------------------------------------------
@@ -1640,7 +1684,7 @@ double PTheory::Polynom(register double t, const PDoubleVector& paramValues, con
   // expected parameters: tshift p0 p1 p2 ...
 
   double result = 0.0;
-  double tshift;
+  double tshift = 0.0;
   double val;
   double expo = 0.0;
 
diff --git a/src/include/PTheory.h b/src/include/PTheory.h
index 31470065..777fcd99 100644
--- a/src/include/PTheory.h
+++ b/src/include/PTheory.h
@@ -52,19 +52,20 @@
 #define THEORY_STATIC_GAUSS_KT               4
 #define THEORY_STATIC_GAUSS_KT_LF            5
 #define THEORY_DYNAMIC_GAUSS_KT_LF           6
-#define THEORY_STATIC_LORENTZ_KT_LF          7
-#define THEORY_DYNAMIC_LORENTZ_KT_LF         8
-#define THEORY_COMBI_LGKT                    9
-#define THEORY_SPIN_GLASS                   10
-#define THEORY_RANDOM_ANISOTROPIC_HYPERFINE 11
-#define THEORY_ABRAGAM                      12
-#define THEORY_INTERNAL_FIELD               13
-#define THEORY_TF_COS                       14
-#define THEORY_BESSEL                       15
-#define THEORY_INTERNAL_BESSEL              16
-#define THEORY_SKEWED_GAUSS                 17
-#define THEORY_POLYNOM                      18
-#define THEORY_USER_FCN                     19
+#define THEORY_STATIC_LORENTZ_KT             7
+#define THEORY_STATIC_LORENTZ_KT_LF          8
+#define THEORY_DYNAMIC_LORENTZ_KT_LF         9
+#define THEORY_COMBI_LGKT                   10
+#define THEORY_SPIN_GLASS                   11
+#define THEORY_RANDOM_ANISOTROPIC_HYPERFINE 12
+#define THEORY_ABRAGAM                      13
+#define THEORY_INTERNAL_FIELD               14
+#define THEORY_TF_COS                       15
+#define THEORY_BESSEL                       16
+#define THEORY_INTERNAL_BESSEL              17
+#define THEORY_SKEWED_GAUSS                 18
+#define THEORY_POLYNOM                      19
+#define THEORY_USER_FCN                     20
 
 // function parameter tags, i.e. how many parameters has a specific function
 // if there is a comment with a (tshift), the number of parameters is increased by one
@@ -75,20 +76,21 @@
 #define THEORY_PARAM_STATIC_GAUSS_KT              1 // damping (tshift)
 #define THEORY_PARAM_STATIC_GAUSS_KT_LF           2 // frequency, damping (tshift)
 #define THEORY_PARAM_DYNAMIC_GAUSS_KT_LF          3 // frequency, damping, hop-rate (tshift)
+#define THEORY_PARAM_STATIC_LORENTZ_KT            1 // damping (tshift)
 #define THEORY_PARAM_STATIC_LORENTZ_KT_LF         2 // frequency, damping (tshift)
 #define THEORY_PARAM_DYNAMIC_LORENTZ_KT_LF        3 // frequency, damping, hop-rate (tshift)
 #define THEORY_PARAM_COMBI_LGKT                   2 // Lorentz rate, Gauss rate (tshift)
 #define THEORY_PARAM_SPIN_GLASS                   3 // rate, hop-rate, order parameter (tshift)
 #define THEORY_PARAM_RANDOM_ANISOTROPIC_HYPERFINE 2 // frequency, rate (tshift)
 #define THEORY_PARAM_ABRAGAM                      2 // rate, hop-rate (tshift)
-#define THEORY_PARAM_INTERNAL_FIELD               4 // phase, frequency, TF damping, damping (tshift)
+#define THEORY_PARAM_INTERNAL_FIELD               5 // fraction, phase, frequency, TF damping, damping (tshift)
 #define THEORY_PARAM_TF_COS                       2 // phase, frequency (tshift)
 #define THEORY_PARAM_BESSEL                       2 // phase, frequency (tshift)
 #define THEORY_PARAM_INTERNAL_BESSEL              5 // fraction, phase, frequency, TF damping, LF damping (tshift)
 #define THEORY_PARAM_SKEWED_GAUSS                 4 // phase, frequency, rate minus, rate plus (tshift)
 
 // number of available user functions
-#define THEORY_MAX 20
+#define THEORY_MAX 21
 
 // maximal number of parameters. Needed in the contents of LF
 #define THEORY_MAX_PARAM 10
@@ -141,6 +143,9 @@ static PTheoDataBase fgTheoDataBase[THEORY_MAX] = {
         {THEORY_DYNAMIC_GAUSS_KT_LF, THEORY_PARAM_DYNAMIC_GAUSS_KT_LF, true,
          "dynGssKTLF", "dgktlf", "(frequency damping hopping-rate)", "(frequency damping hopping-rate tshift)"},
 
+        {THEORY_STATIC_LORENTZ_KT, THEORY_PARAM_STATIC_LORENTZ_KT, true,
+         "statExpKT", "sekt", "(rate)", "(rate tshift)"},
+
         {THEORY_STATIC_LORENTZ_KT_LF, THEORY_PARAM_STATIC_LORENTZ_KT_LF, true,
          "statExpKTLF", "sektlf", "(frequency damping)", "(frequency damping tshift)"},
 
@@ -206,6 +211,7 @@ class PTheory
     virtual double StaticGaussKT(register double t, const PDoubleVector& paramValues, const PDoubleVector& funcValues) const;
     virtual double StaticGaussKTLF(register double t, const PDoubleVector& paramValues, const PDoubleVector& funcValues) const;
     virtual double DynamicGaussKTLF(register double t, const PDoubleVector& paramValues, const PDoubleVector& funcValues) const;
+    virtual double StaticLorentzKT(register double t, const PDoubleVector& paramValues, const PDoubleVector& funcValues) const;
     virtual double StaticLorentzKTLF(register double t, const PDoubleVector& paramValues, const PDoubleVector& funcValues) const;
     virtual double DynamicLorentzKTLF(register double t, const PDoubleVector& paramValues, const PDoubleVector& funcValues) const;
     virtual double CombiLGKT(register double t, const PDoubleVector& paramValues, const PDoubleVector& funcValues) const;