diff --git a/src/mol-theme/color/carbohydrate-symbol.ts b/src/mol-theme/color/carbohydrate-symbol.ts
index 2a56f21d3a6415f3b07e709b547db1837d37824e..9577e1f89f90bda491f53cd5f253934fbfba62af 100644
--- a/src/mol-theme/color/carbohydrate-symbol.ts
+++ b/src/mol-theme/color/carbohydrate-symbol.ts
@@ -69,5 +69,5 @@ export const CarbohydrateSymbolColorThemeProvider: ColorTheme.Provider<Carbohydr
     factory: CarbohydrateSymbolColorTheme,
     getParams: getCarbohydrateSymbolColorThemeParams,
     defaultValues: PD.getDefaultValues(CarbohydrateSymbolColorThemeParams),
-    isApplicable: (ctx: ThemeDataContext) => !!ctx.structure
+    isApplicable: (ctx: ThemeDataContext) => !!ctx.structure && ctx.structure.carbohydrates.elements.length > 0
 }
\ No newline at end of file
diff --git a/src/mol-theme/color/cross-link.ts b/src/mol-theme/color/cross-link.ts
index 62d3d9a28171ebc0b80c3087c3211e7254253bf8..fe0128663812e13dfc0af3c7825ba47382df91de 100644
--- a/src/mol-theme/color/cross-link.ts
+++ b/src/mol-theme/color/cross-link.ts
@@ -72,5 +72,5 @@ export const CrossLinkColorThemeProvider: ColorTheme.Provider<CrossLinkColorThem
     factory: CrossLinkColorTheme,
     getParams: getCrossLinkColorThemeParams,
     defaultValues: PD.getDefaultValues(CrossLinkColorThemeParams),
-    isApplicable: (ctx: ThemeDataContext) => !!ctx.structure
+    isApplicable: (ctx: ThemeDataContext) => !!ctx.structure && ctx.structure.crossLinkRestraints.count > 0
 }
\ No newline at end of file
diff --git a/src/mol-theme/color/model-index.ts b/src/mol-theme/color/model-index.ts
index 39d398c8824e5531321e4f5fd578a10b792e0ea6..4c94ef32092ebb9c01692a27ac6805f985ad46d1 100644
--- a/src/mol-theme/color/model-index.ts
+++ b/src/mol-theme/color/model-index.ts
@@ -64,5 +64,5 @@ export const ModelIndexColorThemeProvider: ColorTheme.Provider<ModelIndexColorTh
     factory: ModelIndexColorTheme,
     getParams: getModelIndexColorThemeParams,
     defaultValues: PD.getDefaultValues(ModelIndexColorThemeParams),
-    isApplicable: (ctx: ThemeDataContext) => !!ctx.structure
+    isApplicable: (ctx: ThemeDataContext) => !!ctx.structure && ctx.structure.models.length > 1
 }
\ No newline at end of file
diff --git a/src/mol-theme/color/occupancy.ts b/src/mol-theme/color/occupancy.ts
index 3f315c5c2c6fa436641a7f66822b731289050ed0..24a9afb2c8db6971faa12404d79e2c2172dbe923 100644
--- a/src/mol-theme/color/occupancy.ts
+++ b/src/mol-theme/color/occupancy.ts
@@ -63,5 +63,5 @@ export const OccupancyColorThemeProvider: ColorTheme.Provider<OccupancyColorThem
     factory: OccupancyColorTheme,
     getParams: getOccupancyColorThemeParams,
     defaultValues: PD.getDefaultValues(OccupancyColorThemeParams),
-    isApplicable: (ctx: ThemeDataContext) => !!ctx.structure
+    isApplicable: (ctx: ThemeDataContext) => !!ctx.structure && ctx.structure.models.some(m => m.atomicConformation.occupancy.isDefined)
 }
\ No newline at end of file
diff --git a/src/mol-theme/color/uncertainty.ts b/src/mol-theme/color/uncertainty.ts
index d7b78dabf43080ff617baa1dd025511856742730..d9218316e14a7a127f5228a7169c3c34aef3eddd 100644
--- a/src/mol-theme/color/uncertainty.ts
+++ b/src/mol-theme/color/uncertainty.ts
@@ -67,5 +67,5 @@ export const UncertaintyColorThemeProvider: ColorTheme.Provider<UncertaintyColor
     factory: UncertaintyColorTheme,
     getParams: getUncertaintyColorThemeParams,
     defaultValues: PD.getDefaultValues(UncertaintyColorThemeParams),
-    isApplicable: (ctx: ThemeDataContext) => !!ctx.structure
+    isApplicable: (ctx: ThemeDataContext) => !!ctx.structure && ctx.structure.models.some(m => m.atomicConformation.B_iso_or_equiv.isDefined || m.sourceData.data.ihm_sphere_obj_site.rmsf.isDefined)
 }
\ No newline at end of file
diff --git a/src/mol-theme/size/physical.ts b/src/mol-theme/size/physical.ts
index d023e2f8a48750ca515f2a2ed9a1db399be6e521..01d71ca05a3e58f759fc3b24f7104f633907bf14 100644
--- a/src/mol-theme/size/physical.ts
+++ b/src/mol-theme/size/physical.ts
@@ -12,7 +12,7 @@ import { ParamDefinition as PD } from '../../mol-util/param-definition'
 import { ThemeDataContext } from '../../mol-theme/theme';
 
 const DefaultSize = 1
-const Description = 'Assigns a physical size.'
+const Description = 'Assigns a physical size, i.e. vdW radius for atoms or given radius for coarse spheres.'
 
 export const PhysicalSizeThemeParams = {}
 export type PhysicalSizeThemeParams = typeof PhysicalSizeThemeParams
diff --git a/src/mol-theme/size/uncertainty.ts b/src/mol-theme/size/uncertainty.ts
index f87579c8721928a2470264cda1bc471aea6e46d5..39e2abf1f615386383d791ab2c9792ab73b69941 100644
--- a/src/mol-theme/size/uncertainty.ts
+++ b/src/mol-theme/size/uncertainty.ts
@@ -57,5 +57,5 @@ export const UncertaintySizeThemeProvider: SizeTheme.Provider<UncertaintySizeThe
     factory: UncertaintySizeTheme,
     getParams: getUncertaintySizeThemeParams,
     defaultValues: PD.getDefaultValues(UncertaintySizeThemeParams),
-    isApplicable: (ctx: ThemeDataContext) => !!ctx.structure // TODO check if the structure has Uncertainty (B-factor, RMSF, ...) values
+    isApplicable: (ctx: ThemeDataContext) => !!ctx.structure && ctx.structure.models.some(m => m.atomicConformation.B_iso_or_equiv.isDefined || m.sourceData.data.ihm_sphere_obj_site.rmsf.isDefined)
 }
\ No newline at end of file